Joey Barton has been issued with a notice of complaint by the Scottish Football Association after being accused of betting on football matches.
The SFA issued a statement yesterday afternoon in which it alleged the Rangers midfielder placed 44 bets between July 1 and September 15 this year.
Barton has until next Wednesday to respond, with a principal hearing date set for Thursday, October 27.
It emerged last month that Barton was under investigation by the SFA and Gambling Commission after claims he had bet on Celtic to suffer a heavy defeat to Barcelona in their opening Champions League match.
The statement from the SFA revealed that the allegations against the 34-year-old, who is serving a club imposed three-week ban after a training ground altercation, run far deeper.
"Disciplinary Rule 31: In that between 1st July and 15th September 2016, both dates inclusive, you placed 44 bets upon football matches, and accordingly gambled upon football matches in contravention of Disciplinary Rule 31," the SFA statement read.
The SFA has a strict no-betting policy on football games and if found guilty Barton could face a ban.
Two former Rangers players are among those to have been punished for breaching the SFA's blanket ban on football betting.
Goalkeeper Steve Simonsen missed one game after betting on 55 matches and Ian Black earlier served a three-match suspension for gambling on 140 matches, including several he played in. The midfielder scored in a 4-2 victory over East Stirlingshire after predicting the Gers would draw in an accumulator.
But the SFA charge leaves Barton even more vulnerable after his club suspension cast major doubt on whether he would play for Rangers again.
Barton is due to return to training at Rangers on Monday after he was told to stay away from the club for three weeks in the messy aftermath to the club's 5-1 Old Firm derby defeat to Celtic on September 10.
Barton was initially banished from the club after he was involved in a training ground row with team-mates following the Celtic Park defeat.
Talks with manager Mark Warburton and board members then failed to resolve the situation and the England cap was told to stay away from the club for three weeks.
Barton - who has just had his autobiography published - was also told not to speak to the media after further angering Warburton by giving a radio interview when he claimed the manager's decision to send him home had been "strange''.