HONG KONG, July 6 (AP) -- Australian jockey Chris Munce has been released without charge after his arrest in Hong Kong on suspicion of bribery, a spokesman for the territory's anti-corruption agency said Thursday.

Munce was among seven people arrested Monday as part of a police investigation into a tips-for-bets scam. Four suspects are accused of serving as illegal bookmakers and the other two are allegedly middlemen.

All seven were released without charge on Tuesday night and Wednesday, pending further investigations, said Lewis Tam, a spokesman for the Independent Commission Against Corruption.

Tam refused to provide more details, but the South China Morning Post said Munce was released after surrendering his passport to anti-graft officers.

The jockey's lawyer, John McNamara, didn't immediately respond to a reporter's call.

Meanwhile, the Hong Kong Jockey Club has begun investigations into the allegations and has taken "initial evidence" from Munce, the club said in a statement.

The corruption commission alleges that Munce gave tips to illegal bookmakers and punters, who repaid the favor by giving him unspecified "advantages" and placing bets for him, and relaying the winnings to him.

Munce was arrested shortly before he was due to return to Australia after finishing a one-year riding contract for the Hong Kong Jockey Club.

The jockey is one of Australia's most successful riders. He ranked third in the 2005-6 Hong Kong racing season and won the Melbourne Cup in 1998, as well as a Cox Plate _ a major pre-Melbourne Cup race -- in 2004. He also won Golden Slippers in 1998 and 2004.