In the second successive case of its kind , Singapore's former civil defence chief Peter Lim, 52, was charged with obtaining oral sex in 2010 from Pang Chor Mui, then general manager of Nimrod Engineering, an equipment supplier to the Singapore Civil Defence Force (SCDF).
The trial opened three days after the former head of the narcotics police, Ng Boon Gay, was cleared of corruption when a judge rejected charges that he demanded oral sex from a contractor to help her win government deals.
The new trial "involves a high ranking civil servant who abused his official position and corruptly obtained gratification from a general manager of a company which was a vendor to the organisation" he led, state prosecutors said.
The contractor feared she would "jeopardise" her company's "existing good relations" with the SCDF "if she did not give in to his request for oral sex", they said in a prepared opening statement given to the media.
Prosecutors said Lim had the authority to give final approval to contracts worth up to Sg$1.0 million ($800,000).
They alleged that Lim called Pang after the sexual encounter to ask about the supply of radiation monitoring equipment even before the SCDF issued a public tender.
With information provided by Lim, Nimrod sourced suppliers and submitted a bid, the prosecutors alleged without stating if Nimrod won the contract.
Lim, who is under suspension, faces nine other charges of obtaining sex from two other women whose companies also sold products to the SCDF, which provides firefighting, ambulance and other emergency services.
Prosecutors said the other charges would be dealt with separately at a later date.
Defence lawyer Hamidul Haq told the district court his client "categorically denies any allegations of corruption made against him".
Haq said Lim and Pang shared an intimate friendship and had a "one-off" encounter.
"The friendship between our client and Ms Pang had no bearing whatsoever on the outcome of these tenders," Haq said.
High-level corruption cases are rare in Singapore, which is known for its efficient and well-paid bureaucracy.