Former Wallaby Justin Harrison has quit his English rugby union club Bath, raising doubts over whether he will play in the Barbarians tour of Australia.

Several British newspapers on Wednesday reported Harrison had left Bath and was on his way back to Australia after asking for an early release from his contract amid an inquiry into claims several of the club's players were involved in a drunken brawl.

Britain's Daily Mail newspaper said Harrison, 35, had also pulled out of the Barbarians' scheduled matches against England at Twickenham next week and Australia in Sydney on June 6.

A Barbarians source told the newspaper: "Harrison withdrew on Sunday saying he had some domestic matters to deal with in Australia."

Harrison joined Bath from Ulster on a one-year contract in 2008 and signed a 12-month extension last December.

Several Bath players are alleged to have been involved in a punch-up at a London nightclub on May 10, the day after the club lost to Leicester in the semi-finals of the English Premiership.

The News of The World tabloid reported at the weekend that several players had refused to provide samples for drug tests after drinking sessions the same weekend.

"Bath Rugby are continuing with their ongoing investigations regarding an alleged incident," Bath's chief executive Bob Calleja said in a statement.

"Until the club is satisfied that it has established and considered all of the relevant facts the club will not be making any further comment."

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