LONDON: The FA have received details of a furious confrontation in the referee's changing room at Stamford Bridge involving angry Chelsea officials, Mark Clattenburg and John Obi Mikel, reported Daily Mirror.

Clattenburg (pic) is believed to have referred to an 'extraordinary incident' in his report of the Blues' highly-charged loss to Manchester United.

It emerged late on Monday that the words "I'm gonna f******g break your legs" were heard during a furious post-match bust-up.

They came from inside the referee's dressing room as Clattenburg and his officials were angrily confronted by Chelsea staff and Mikel, the man the Blues claim was racially abused by the Gosforth official on Sunday.

The Mirror understands the scenes became so heated, onlookers described the intervention of security staff as resembling "bouncers at a pub brawl".

The bust-up came after Chelsea had two men sent off in United's explosive 3-2 win.

It also came as the European champions claimed Clattenburg had used language which could be interpreted as racist towards Mikel and Juan Mata.

The fall-out from the match continued on Monday, as the police received a complaint relating to the incident and referees' union Prospect leapt to Clattenburg's defence.

Prospect said in a statement: "Prospect are  committed to helping to eradicate racism in football and in society generally.

"In the context of that commitment, Prospect is offering full support to  Mark Clattenburg in relation to the allegations made against him."

Clattenburg is allowed to continue refereeing, but has been stood down for this weekend's Premier League games by the Professional Game Match Officials.

They said: "With any football match, the focus should not be on the officials but on the players and the game itself.

"Mark Clattenburg is one of the elite referees in world football and, in these circumstances, the intense level of scrutiny would detract from the match and be unfair to the clubs and the supporters of both sides."

Meanwhile, the FA launched a formal probe into Chelsea's complaint.

Mindful of the criticism they attracted in the wake of the lengthy John Terry investigation, FA chiefs realize it is in everyone's interests to establish the facts of the case as quickly as possible.

A statement said: "'The FA have begun an investigation relating to allegations made following Sunday's fixture at Stamford Bridge between Chelsea and Manchester United.

"The FA will make no further comment at this time."

The FA will now speak to Clattenburg, his assistants Michael McDonough and Simon Long and fourth official Michael Jones.

They are also set to make fresh contact with Chelsea, to ask for their version of events.

And the FA are set to review TV footage, although the Mirror understands they had not formally requested it from match broadcaster Sky Sports as of Monday night.

- mD