Peter Lim Sin Pang, the former civil defence chief who was convicted of corruption, will serve out the remainder of his six-month jail term at home.
The Singapore Prison Service, responding to queries, confirmed that the 53-year-old was let out of Changi Prison and placed on home detention on Sept 27.
Lim was found guilty in May of corruptly obtaining sex from a 49-year-old sales director who had worked for Nimrod Engineering, a vendor of the Singapore Civil Defence Force (SCDF). This was in exchange for furthering the business interests of Nimrod.
He also admitted to seven more corruption charges involving trysts with two other women who were working for separate vendors of the SCDF.
Like former law professor Tey Tsun Hang, who was jailed for five months in June for corruption, and later served part of his sentence on home detention, Lim needs to adhere to certain conditions under the scheme.
He will be subjected to electronic monitoring, allowed to leave home only between noon and 3pm, and must not speak with the media.
And if he commits an offence while on home detention, he will face disciplinary or legal action, which may result in his home detention order being revoked, said a prison service spokesman.
As the former commissioner of the SCDF, Lim is one of the most high profile inmates to be put on home detention.
The programme was started in 2000 as part of a move by the prison service to help inmates re-integrate back into society. To date, some 16,000 inmates have been through the scheme.
To be eligible, an inmate would need to be sentenced to jail for at least four weeks, and have served no less than two weeks of his sentence.
Not everyone is eligible. Those who cannot be considered for home detention are inmates serving a life imprisonment sentence, or if they have been convicted of attempted murder, voluntarily causing grievous hurt by dangerous weapons, rape, robbery, and other serious or violent crimes under a Prisons Act schedule.
Besides the nature of the crime committed, various other factors are considered in assessing the suitability of an inmate for home detention. "The person's conduct, response to rehabilitation in prison, level of family support, and the risk of re-offending are factors that are also considered," said the prison service spokesman.
He added that the prison authorities are also assisted by an independent advisory committee with regard to the placement of inmates on home detention.
This committee is made up of members of the Board of Visiting Justices, community leaders and private sector professionals.
Lim was one of two senior public servants who found themselves on the wrong side of the law last year. This, after a graft probe against them made the news.
The other man in a separate sex-for-contracts case was former Central Narcotics Bureau chief Ng Boon Gay.
While Mr Ng was acquitted of all charges this year after a lengthy trial, Lim - who is married with a daughter - was dismissed from public service after he was convicted.