Mas Selamat Kastari (born 23 January 1961), a Muslim Indonesian-born Singaporean, was for more than a year Singapore's most-wanted fugitive after escaping from detention on 27 February 2008.

[4] However, Mas Selamat has never been formally charged with any terrorism-related offences;[1] instead, he was detained under the country's Internal Security Act, which allows indefinite detention without trial.

[7] Born in 1961 in Kendal, Central Java, in Indonesia, Mas Selamat grew up in Kaki Bukit in Singapore leading a typical childhood kampung life.

During this period of imprisonment, he broke his left leg in a botched attempt to escape when he jumped from a high floor, resulting in him walking with a permanent limp.

[6] At 4:05 pm on Wednesday, 27 February 2008, the JI leader escaped from the Internal Security Department's Whitley Road Detention Centre where he was being detained.

[12] Deputy Prime Minister Wong Kan Seng acknowledged that a security lapse led to his escape, and that everything was being done to recapture Mas Selamat.

An urgent worldwide security alert, or Orange Notice, was issued by INTERPOL to each of its 186 National Central Bureaus following a request from Singapore.

[35] Agence France-Presse noted, "Terrorism is usually no laughing matter, especially not in security-conscious Singapore, but the escape from custody of a limping Islamist extremist suspect has led to scorn on the Internet.

[36] Speculations and conspiracy theories abounded in Internet chatrooms and blogs, such as that Mas Selamat had died in detention or that he was purposefully let out in order to allow authorities to search for other terrorists.

[37] Criticism has been directed towards Wong Kan Seng, the Minister of Home Affairs in Singapore, with regards to the fact that news of Mas Selamat's escape was not disseminated to the public until four hours after its occurrence.

[38] On 2 March 2008, it was announced that an independent Committee of Inquiry, chaired by former judge Goh Joon Seng, would be set up to find out how the escape occurred.

Nine individuals, including the commander and his superior holding a rank equivalent to brigadier general, were penalised for lapses that allowed Mas Selamat Kastari to escape from the Whitley Road detention centre.

Mas Selamat had turned on the water tap after closing the toilet door and the guards on duty only acted on their suspicions 11 minutes after this incident.

[47] Malaysian Home Minister Hishammuddin Hussein confirmed that Mas Selamat was being held under the Internal Security Act, saying that he was "planning something, which allowed us to arrest him".

[49] According to the media, Mas Selamat was captured in the early morning of 1 April in a secluded house in Kampung Tawakal, an obscure village with a population of less than 100 in Skudai, 25 kilometres (16 mi) northwest of Johor Bahru.

[50] Prior to his arrest, Mas Selamat had limited contact with outsiders, even avoiding prayers at the local surau, but had been witnessed tending to the compound's garden.

[52] As of December 2021[update], Mas Selamat remains imprisoned behind bars indefinitely under the Internal Security Act while still "deeply entrenched in (his) radical beliefs".