Chinese snooker player Zhao Xintong has withdrawn from the Hong Kong Masters tournament after testing positive for Covid.

The 25-year-old player was one of six international stars at the event, the first international snooker tournament held in Asia since the pandemic. He will be replaced by three-time world champion Mark Williams, organisers said.

Zhao, who won the prestigious UK Championship last November, tested positive on Wednesday evening after arriving in the city the day before, according to the organisers.

Hours before testing positive, Zhao appeared alongside fellow players Ronnie O'Sullivan, Judd Trump, Mark Selby, John Higgins and Neil Robertson at a press conference.

Players have to abide by the "zero plus three" policy and are given an amber health code, barring them from dining out.

The world's top-ranked player, Ronnie O'Sullivan of England, had said he has no problems with the restrictions.

Selby and Hong Kong's Marco Fu will kick off the event on Thursday at the Hong Kong Coliseum, which will operate at 85 percent capacity under social distancing rules, with organisers expecting 9,000 spectators for Sunday's finals. (Additional reporting by AFP)