Former NSL player Brian Bothwell is one of four foreign players who have been arrested in connection with a local match-fixing probe, according to the Straits Times newspaper.
The players - Billy Bone, Brian Bothwell, Max Nicholson, and Lutz Pfannenstiel - were questioned by Singapore's Corrupt Practices Investigation Bureau on Monday and released on bail of S$15,000 ($A14,980) each, the paper said.
Bone, Bothwell and Nicholson are British. Pfannenstiel is German.
Three play for the local S-League's Geylang United club and Nicholson for Woodlands Wellington.
Bone, 28, was quoted as saying that he and Bothwell would release a statement in due course.
"But at this moment let us just say that we're helping the authorities with their investigations," the newspaper quoted him as saying.
Singapore launched legalised betting on S-League games in 1999 in a move that was seen combatting illegal bookies and allegations of match-fixing.
Singaporeans were expected to spend as much as S$250 million on S-League betting in its first few years.
In 1999, Singapore's Inland Revenue Authority collected S$1.32 billion in taxes from betting, sweepstakes and private lotteries.
In 1994, a major bribery scandal emerged when the Singapore police arrested a striker and referee for fixing six matches in the 16-team Malaysian league.