The players -- Billy Bone, Brian Bothwell, Max Nicholson, and Lutz Pfannenstiel -- were questioned by Singapore's Corrupt Practices Investigation Bureau and released on Monday on bail of S$15,000 (US$8,668) 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.

Two other foreign players were assisting in the investigation, the newspaper said.

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.

The scandal led to the banning of a fifth of the league's players and the withdrawal of Singapore from the league.

The newspaper said speculation about match-fixing in S-League games had been rife recently.