Joey Barton, Newcastle United's troubled midfielder, was arrested by Merseyside police after an incident in Liverpool city centre in the early hours of yesterday morning.
Hours after Newcastle's 1-0 defeat at Wigan Athletic, Mr Barton, 25, is alleged to have taken part in an assault outside a branch of McDonald's and was arrested at 5.30am.
Another man, aged 19, and a woman aged 27 were also arrested and taken for questioning at a local police station. All three were in custody yesterday evening.
If Mr Barton is charged it could have serious ramifications for his career at Newcastle and for his future in professional football. He could even be in breach of his contract at Newcastle.
Mr Barton, 25, has previously been involved in controversies. He hit the headlines on Tyneside recently when he said that the abuse Newcastle fans directed at players and manager Sam Allardyce during the home defeat by Liverpool was "vicious".
Mr Barton's description was actually part of a call for unity among fans and staff at the under-performing club but that relationship has been tested again since and the strains were heard during Wednesday's defeat at Wigan.
Signed by Allardyce in the summer for 5.8m, Mr Barton's Newcastle career has been hampered by a foot injury and the team's inconsistencies.
The arrest is further bad news for Allardyce, who is under pressure to keep his job at Newcastle. He knew that signing Mr Barton was a gamble and said so during the summer.
"There's nothing wrong with Joey's football, but the off-field situation is something we have to work on and it has to be better," Allardyce said. "On the pitch, he's a tremendous player and he'll be a terrific asset for Newcastle United. He's a big, big character someone who likes to say what he thinks. That's getting slightly rarer in today's game, but he goes out and proves he can do what he says."
On off-the-field matters, Allardyce continued: "It's between me and Joey, but that side of it had to be a consideration, of course. I had to convince the board that myself and Joey would be able to deal with that side and not let that side of it come out yet again.
"Me, this football club and Joey cannot run into trouble off the field, because if he wants to be successful here and he has ambitions to play again for England he's more than capable of it."
sport, page 72
Highs and lows of his career
* November 2002: Hailed as future star for Manchester City. When Kevin Keegan calls him out for first-team debut, he can't find his shirt it has been stolen.
* April 2003: Scores his first goal, against Tottenham Hotspur. Signs lucrative deal with Man City.
* August 2003: Scores second goal, against Blackburn Rovers.
* September 2003: Called into England Under-21 squad.
* Summer 2005: Sent home from pre-season tour of Thailand after row with Everton fan, 15.
* January 2006: Criticised by Manchester City fans when he hands in transfer request.
* September 2006: Exposes backside to an Everton fan at Goodison Park.
* February 2007: Makes his England debut against Spain.
* June 2007: Leaves Man City for Newcastle United for 5.5m.
* November 2007: Kicks Sunderland player in groin.