colonial government. St John’s received its first batch of detainees on 20 September 1948, comprising 200 political prisoners from Johore Bahru. Travellers via ship suspected of communist inclinations were also detained at St John's under the Emergency Travel Restrictions Regulations until they were cleared of suspicion. Within two years, more than 600 were detained under the Emergency Regulations, most of whom were held on St John's. Singaporean political prisoners detained on St John's Island were university students, teachers, newspaper editors, several future politicians of Singapore, and others. Among the detainees were Devan Nair, Fong Swee Suan and Lim Chin Siong, all People's Action Party (PAP) members. They were released in 1959 after Singapore was granted full internal self-government and the PAP won the 1959 Singapore general election. The state's fear of communism did not abide, resulting in St John's being used as a detention centre for most of the detainees arrested during the anti-communist Operation Coldstore. On 2 February 1963, the Internal Security Council of the Singapore Government executed Operation Coldstore, which detained those charged as political extremists under the Preservation of Public Security Ordinance. Arrestees were detained without trial, some for being a "suspected communist" or for associating with them. The state justifies Operation Coldstore as a response to communist threats. Prior to the move to St John's, the detainees were held in Outram Prison. On 6 February, it was announced that 99 of the 113 Operation Coldstore detainees were to be moved to the island. The rest were citizens of the Federation of Malaya, who were to be expatriated. The operation has been a contentious subject of criticism, such as from ex-detainee Poh Soo Kai and historian Thum Ping Tjin who claim that Operation Coldstore was a pretext for the PAP to crush political opposition. Drug rehabilitation centres From 1945 onwards, the British sought to curb opium addiction in Singapore and this led to the establishment of St John’s Opium Treatment Centre. Opium was prevalent in Singapore with more than 16,000 addicts recorded after World War II. By 1945, the British Administration of Malaya sought to curb its effects and banned opium in its colonies in October. The following year, the Opium and Chandu Proclamation further restricted drug activity by banning opium smoking and the possession of opium-smoking devices. Despite these regulations, there were still more than 1,400 opium dens in 1949. In the 1950s, the government tackled