Prior to the riots, the disputed custody of Maria had received widespread press coverage. Many Muslims living in Malaya and Indonesia believed in the legitimacy of the adoption of Maria and a later short-lived marriage to Mansoor Adabi, two major points of contest in the court proceeding to determine the custody of Maria. They thus lent their support, financial and moral, to organizations that fought to keep Maria in Malaya. But some, such as the Malayan nationalists, seized the incident as an opportunity to further weaken the colonial government's position in the region. The insensitivity of the colonial government towards Muslim sentiments and the involvement of radical elements eventually culminated in the tragedy.
When World War II broke out, Sergeant Hertogh was captured by the Imperial Japanese Army and sent to a POW holding facility in Japan, where he was kept till 1945. Meanwhile, Adeline Hertogh stayed with her mother, Nor Louise, and her five children, among whom Maria was the third and youngest daughter. On December 29, 1942, Mrs. Hertogh gave birth to her sixth child, a boy. Three days later, Maria went to stay with Aminah binte Mohammad, a 42-year-old Javanese woman and a close friend of Nor Louise. This controversial transfer of custody, reversed in a Singaporean court eight years later, was the centre and opening episode of the tragic riots that were to come.
From her internment camp, she smuggled a letter to her mother, requesting for her children to be sent to her. This Nor Louise did, but Maria was not among them. So Mrs. Hertogh asked her mother to fetch Maria from Aminah. Her mother later wrote and told her that Aminah wanted to keep Maria for two more days, after which she herself would bring the child to the camp. This did not materialize and Mrs. Hertogh did not see Maria throughout her internment. After her release, she could find neither Maria nor Aminah.
Aminah also contested the truth of Adeline Hertogh's internment by the Japanese. She testified that she and Mrs. Hertogh continued to visit each other frequently after the adoption until the latter left for Surabaya to look for a job "about the end of 1943 or the beginning of 1944." Thereafter the two never saw each other again till 1950.
Then, in 1947, fearing harm upon the family during the Indonesian National Revolution as Maria was a "Putih", or a "White Child", Aminah moved via Singapore to her hometown in Kemaman, in the state of Terengganu, then Malaya. By then Maria was completely the same as any other Malay Muslim girl of her age: she spoke only Malay, wore Malay clothes and practised her religion devoutly.
Negotiations were opened to retrieve Maria in early 1950. The Dutch Consulate offered S$500 to make up for Aminah's expenses in bringing up the girl for eight years. Aminah rejected the offer and refused to give up her foster-daughter. Nonetheless, she was persuaded to travel with Maria to Singapore in April to discuss the issue with the Dutch Consul-General. However, Aminah's firm position could not be wavered and the Consulate eventually applied to the High Court on 22 April for Maria to be delivered into the custody of the Social Welfare Department pending further order. The Chief Justice heard it on the same day and approved the application ex parte.
The next day, an officer from the department served the order on Aminah and brought Maria away. After a routine medical examination at the Middle Road Hospital, she was admitted to the Girls Homecraft Centre at York Hill. From this point onwards, Maria had made it clear that she wanted to stay with Aminah and did not wish to be returned to her natural parents. However, the High Court ruled on 17 May after a short hearing of about 15 minutes that the custody of Maria be entitled to the Hertoghs.
As Aminah and Maria exited the court via the backdoor, a car from the Consulate was waiting to take Maria away. Maria refused to enter the car and clung on to Aminah, both shouting in Malay that they would kill themselves rather than be separated. A large crowd quickly formed around the commotion. It was only after much persuasion that Aminah agreed to enter the car together with Maria and pay a visit to her lawyer, who explained that Maria had to be given up until an appeal was made. The duo then parted in tears, with Maria returned to York Hill for temporary safekeeping.
At York Hill Maria stayed for two more months, under a further order from the Chief Justice pending appeal, which was filed on 28 July. The verdict was an overruling of the earlier decision. Aside from the ex parte order to hand Maria to the Social Welfare Department, the Appellate Court found ambiguity in the Dutch Consul-General's representation of Maria's natural father, a rather minor and technical detail but apparently significant enough under the circumstance. Both Aminah and Maria were overjoyed.
The first challenges on the appropriateness of the marriage actually came from the Muslim community. On 10 August, a Muslim leader wrote to The Straits Times pointing out that although the Islamic law permits the marriage of girls after puberty (which Maria had reached a year earlier), there were Muslim countries such as Egypt that legislated for a minimum marriage age of 16. He added, however, that it would not be in the interest of "the friendly understanding... between Christians and Muslims" to object to the marriage since it had already taken place. The latter view was held by the Muslim population at large, albeit in a more antagonistic mood against the Dutch and Europeans at large.
The hearing did not begin till 20 November. For four months the matter hung in suspense. During this time, Maria rarely left her residence in the house of M.A. Majid, then president of the Muslim Welfare Association, because in her own words, she attracted "too much attention". Nevertheless, media coverage on the incident had grown to a global scale. Letters from Muslim organizations in Pakistan promising financial and other help arrived, some going so far as to declare any further move by the Dutch Government to separate the couple as "an open challenge to the Muslim world". Pledges of aid also came from Indonesia and as far as Saudi Arabia.
The hearing finally opened, and Maria's natural mother, Adeline Hertogh travelled down to Singapore to attend. The judge, Justice Brown, delivered the verdict two weeks later. The marriage, instead of resolving the dispute, had instead complicated it. Justice Brown had two issues on his hand, namely the legality of the marriage and the custody of Maria. He held that the marriage was invalid because:
Having overruled the purported marriage, Justice Brown went on to deal with what he described as the "most difficult" question of custody. He noted that his duty to the law required him "to have regard primarily to the welfare of the infant". He believed this meant that he not only had to consider the current wishes of Maria, but also her future well-being. He stated:
''It is natural that she should now wish to remain in Malaya among people whom she knows. But who can say that she will have the same views some years hence after her outlooks has been enlarged, and her contacts extended, in the life of the family to which she belongs?"
He also noted that whatever the details of the contested initiation of the custody at the end of 1942 might be, Adrianus Hertogh had not been part of it and had not abrogated his parental rights. He therefore awarded the custody of Maria to the Hertoghs and ordered that she should be handed over to her mother with immediate effect.
The car delivered Maria to the Roman Catholic Convent of the Good Shepherd in Thomson Road. Mrs. Hertogh stayed at another address for a few days, from where she visited Maria daily, before moving in to the convent herself. According to an official of the Netherlands Consulate-General, such arrange was because of "greater convenience" while the stay of execution pending appeal was in effect. But it proved to be the falsest step, the spark that lit the fuse of the subsequent riots.
First and foremost, the press was not barred from entering the convent grounds. Nor were they restricted in any way in their approach to the incident, which had been nothing shy of sensational. On 5 December, the Singapore Standard published on its front page a photograph of Maria standing holding hands with the Reverend Mother. There were several more pictures on page 2, under the headline: Bertha knelt before Virgin Mary Statue. The Malay press retorted. The Utusan Melayu published on 7 December three photographs of Maria weeping and being comforted by a nun, as well as articles about Maria's "lonely and miserable" life in the convent.
These pictures, whether presenting Maria as happy or sad, mostly showed Maria surrounded by symbols of Christian faith. The Muslims, who looked upon Maria as one of their own, were deeply offended by such pictures, not to mention the sensational reports, some of which explicitly labelled the case as a religious issue between Islam and Christianity.
On 9 December, an organization calling itself the Nadra Action Committee was formally constituted under the leadership of Karim Ghani, a Muslim political activist from Rangoon. This extreme organization solicited support among local Muslims by distributing free copies of its newspaper, the Dawn (not the Dawn, an English paper published in Pakistan). Karim Ghani had also made an open speech at the Sultan Mosque on 8 December in which he mentioned jihad as a final resort.
In the light of these potent signs of a great disturbance, the Criminal Investigation Department sent a memo to the Colonial Secretary suggesting moving Maria back to York Hill to avoid further inciting Muslim anger. The Secretary did not agree on grounds that he had received no such representations from Muslim leaders, nor did he have the authority to remove Maria without further court orders - weak excuses since Maria could be relocated with her mother's consent. Nonetheless, it could never be said if moving Maria out of the convent at such a late stage could have averted the riots.
The mob (largely consisted of Malay or Indonesian Muslims but local Chinese gangs were also reported to have joined in) moved out to attack any Europeans and even Eurasians in sight. They overturned cars and burnt them. The police force, its lower ranks largely consisted of Malays who sympathized with the rioters' cause, were ineffective in quelling the riots. By nightfall the riots had spread to even the more remote parts of the island. Help from the British military was enlisted only at around 6:45 PM. Major-General Dunlop promptly deployed two Internal Security Battalions while calling in further reinforcements from Malaya. Meanwhile, various Muslim leaders appealed over the radio for the riots to cease.
Reinforcements arrived early on 12 December, but riotous incidents continued on that day. The troops and police only managed to regain control of the situation by noon on 13 December. In total, 18 people were killed, among whom were seven Europeans or Eurasians, two police officers, and nine rioters shot by the police or military, 173 were injured, many of them seriously, 119 vehicles were damaged, and at least two buildings were set on fire. Subsequently, two weeks of 24-hour curfew were imposed, and it was a long time before complete law and order was re-established.
On 25 August, 1951, Tunku Abdul Rahman, who would later become the first Prime Minister of Malaysia, took over as the president of UMNO, a Malay and therefore Muslim party, that remains the largest and ruling political party in Malaysia today. He immediately set out to save the seven on death row. Having garnered support from the Muslim population, Abdul Rahman placed pressure on the authorities, who finally gave in. The British government was expecting their role as the colonial master to end very soon and did not wish to leave behind grim memories. The death sentences for all five were commuted to life imprisonment.
Present day Government of Singapore also attributed the tragedy to the insensitivity of the colonial government towards the racial and religious feelings of the locals. It cites the incident as a vital lesson learnt in the importance of racial and religious understanding and harmony. It also cites the incident as a case for placing a certain degree of governmental control on the media, especially when racial or religious issues are implicated.
At first, Maria could only talk to her mother, the only one in the family who understood Malay. She demanded rice with every meal, resenting the western diet. She continued to say her Muslim prayers five times a day. In addition, a policeman in plain clothes was assigned to escort her whenever she left the house, for fear of possible kidnappers who might take her back to Singapore, following reported sighting of "oriental strangers" around town. The house was also placed under surveillance.
Slowly, Maria began to adjust to her new environment. A nun came to the house daily to teach her Dutch until she was proficient enough to attend a local convent school. She also began to attend Mass with her family. Back in Singapore, Aminah and Mansoor had apparently given up hope of retrieving Maria after leave to appeal to the Privy Council was not granted. Earlier interest of the several Muslim groups involved had also gradually died down.
On 20 April, 1956, Maria was married to Johan Gerardus Wolkefeld, a 21-year-old Dutch Catholic. On 15 February, 1957, she gave birth to a son, the first child of ten. However, Maria did not seem to be content. As she told De Telegraaf, she often had rows with her mother, who lived near by. She also said she still longed for her Malayan homeland. Johan and Mansoor began corresponding. In letters both expressed wish for Maria to travel to Malaya to visit the aged Aminah, but such trip was never made due primarily to financial difficulties. Aminah died in 1976.
The life story of Maria took another dramatic turn on 16 August of the same year, when Maria found herself on trial in a Dutch court charged with plotting to murder her husband. She admitted in court that she had been thinking about leaving her husband but was afraid to start divorce proceedings in case she lost custody of her children. She came into contact with two regular customers at her husband's cafe bar. The trio bought a revolver and recruited a fourth accomplice to carry out the actual murder. However, the latest member got cold feet and gossiped about the murder plan. The police quickly learnt of it and arrested all four conspirators.
In her defence, Maria's lawyers brought up her background, which the court acknowledged. With this in mind, and because the plot was never executed and there was no proof that she offered any inducement to the other three, the three-men bench acquitted Maria. Meanwhile, Maria had also filed for divorce on the grounds of the irreparable breakdown of her marriage.