Police are investigating an allegation of common assault made against Jose Mourinho after a Champions League tie.

It has been alleged the Inter Milan manager punched a supporter as he left Old Trafford stadium after his team's defeat by Manchester United.

Police have contacted United to request CCTV footage of the area and have confirmed a complaint has been made.

A spokesman for Manchester United confirmed they are aware of the allegation but made no further comment.

The fan is alleged to have chanted, "You're going home, you're going home" to the former Chelsea manager.

He later went into Stretford police station, close to Old Trafford, to report the alleged attack.

A Greater Manchester Police spokesman said: "Just before midnight on Wednesday 11 March 2009 a man reported he'd been punched in the face outside Old Trafford.

"Police are investigating this common assault allegation. Inquiries are ongoing."

The allegation came after Mourinho watched his team crash out of the Champions League after Nemanja Vidic and Cristiano Ronaldo scored for United at the start of each half.

Mourinho has come under attack from the Italian media for his failure to get Inter through to the last eight teams in the competition.

The plane taking the Inter party back to Milan left Manchester at 0025 GMT.

The 'Special One' considered the 2-0 defeat at Old Trafford unfair, but stated that Manchester United were the better side.
"The result of this game seems unfair, Inter made a great game, played according to their capacities," he told RTP.
"Analysing things from a much more global point of view, they are better than us, and since they are better, they are through."
Mourinho, who has guided teams to win the UEFA Cup, Champions League and the Premier League in the past, has now revealed that the Serie A title will be the most important of them all.
"These eight months? It has been a great experience, obviously with big difficulties, and if I win the Serie A like I hope, it will be the biggest accomplishment of my career."

Manchester United striker Wayne Rooney insists Jose Mourinho was no factor during last night's victory over Inter Milan.
The result was the first time a Mourinho team had conceded two goals to Manchester United and Rooney said: “We're delighted we're through.
“To be honest I didn't even know that fact about Mourinho sides, I wasn't aware of it.
“The game is not about Mourinho, it's about Man United and Inter Milan, and thankfully we got through. I'm not really too bothered who we get in the next round now. Whoever we get we know it will be a difficult game because there are no easy games at this stage of the competition.
“The important thing is we're doing well and winning games and we want that to continue. We will just keep trying to win the games and go as far as we can this season.”