Rangers player Joey Barton is being investigated by Scottish football officials for allegedly breaking betting rules, according to reports.

The controversial midfielder is already on a three-week ban from the club after a training ground altercation following a 5-1 defeat to Celtic.

The 34-year-old is now being investigated by the Scottish Football Association and the Gambling Commission over claims he bet on Celtic suffering a heavy defeat to Barcelona last Tuesday.

Brendan Rodgers' side lost 7-0 in their Champions League match at the Nou Camp.

The SFA has a no-betting policy on games and if found guilty Barton could face a ban.

Two former Rangers players are among those to have been punished for breaching the rule.

Goalkeeper Steve Simonsen missed one game after betting on 55 matches and Ian Black served a three-match ban for gambling on 140 matches, including several he played in.

There is already doubt whether Barton will play for Rangers again after his training ground bust-up.

He was initially banished from the club for five days - and this was extended for a further three weeks on Monday after talks with manager Mark Warburton and board members failed to resolve the situation.

The club has told him not to talk to the media after he angered Warburton by calling the ban "strange" in a radio interview on Friday.

It is understood last Tuesday's altercation was not the first time he has argued with his new teammates.