PA Sport reports the controversial former Manchester City and Burnley midfielder was banned from the club on Monday for three weeks after a training ground altercation following the 5-1 defeat to Celtic.
The Scottish Football Association and the Gambling Commission are looking into claims that the 34-year-old bet on Celtic to suffer a heavy defeat to Barcelona last Tuesday night. Brendan Rodgers' side lost 7-0 in their Champions League Group C opener in the Nou Camp.
The SFA has a strict no-betting policy on football games. If found guilty Barton could face a ban but is unlikely to face a major punishment if the alleged gambling was restricted to one incident.