The case, which charges Iswaran with receiving favours that includes tickets to English Premier League soccer matches and to the Singapore Formula 1 Grand Prix, has gripped the wealthy city-state which prides itself on having a well-paid and efficient bureaucracy as well as strong governance.
Iswaran, who joined the cabinet in 2006, is the first Singaporean minister to be tried in court on graft charges.
The 62-year-old was arrested in July last year and was accused of taking kickbacks worth hundreds of thousands of dollars from property tycoon Ong Beng Seng. Iswaran was advisor to the Grand Prix's steering committee, while Ong owns the rights to the race.
Ong has not been charged with any offence and Iswaran had previously rejected the allegations when he resigned from the cabinet.
In court, he pleaded guilty to the charges of obstructing justice and of a public servant accepting anything of value without payment, or with inadequate payment, from a person with whom he is involved in an official capacity, Channel NewsAsia (CNA) reported, instead of the charges that include corruption.
In a surprise move, prosecutors reduced the charges facing Iswaran to five from 35. The remaining 30 charges will be taken into consideration for sentencing, it added.
The charge of accepting gifts carries a jail term of up to two years and a fine. For obstructing justice, Iswaran can be sentenced to jail of up to 7 years and a fine.
However, the prosecution asked for a much lighter sentence of six to seven months in jail, while the defence is asking for eight weeks, according to CNA.
Justice Vincent Hoong said he would be sentenced on Oct 3, The Straits Times newspaper reported.
The last corruption case involving a Singaporean minister was in 1986, when the national development minister was investigated for allegedly accepting bribes. He died before he could be charged in court.
Singapore was among the world's top 5 least corrupt countries last year, according to Transparency International's corruption perception index.
