The Scottish Football Association and the Gambling Commission will look into claims that Joey Barton broke football betting rules in last week's Champions League clash between Barcelona and Celtic.
Rangers announced on Monday that Barton, who joined the Scottish club on a free transfer in the summer, had been suspended for three weeks following a training-ground altercation with teammate Andy Halliday.
However, Barton is now facing a ban from the Scottish Football Association, who will look into suggestions that the midfielder bet on Celtic to suffer a heavy defeat in last week's European tie, which the Spanish side won 7-0.
Barton has since apologised for his part in the training-ground bust-up with Halliday, but it has been reported in some sections that the 34-year-old's relationship with Gers boss Mark Warburton is now beyond repair.
Barton's autobiography No Nonsense will be released this week.