Chelsea have accused referee Mark Clattenburg of directing inappropriate language towards two of their players during yesterday’s acrimonious 3-2 defeat against Manchester United, with one complaint understood to relate to a comment of an alleged racial nature.

A formal complaint has been made to the Premier League’s match delegate and will be forwarded to the Football Association, with the Professional Game Match Officials’ Board, the body which represents referees, now awaiting the reports from both Clattenburg and the match delegate.

A spokesman for the referees said last night: “PGMO is aware of the allegations and they are being treated with the utmost seriousness. Mark will co-operate fully and welcomes the opportunity for the facts to be established. No further comment will be made until this matter has been properly investigated.”

It is understood that Chelsea will allege that one player, believed to be John Obi Mikel, has complained that Clattenburg directed a comment of a racial nature at him during the game.

The complaint of the other Chelsea player is understood to allege inappropriate language but not of a racial nature. Mikel, who was booked for dissent during the game, is believed to have confronted Clattenburg in the referee’s room after the game. Chelsea announced that they had made their complaint around two hours after the final whistle.

“We have lodged a complaint to the Premier League match delegate with regards to inappropriate language used by the referee and directed at two of our players in two separate incidents in today’s match,” said a Chelsea statement. “The match delegate will pass the complaint to the Football Association . We will make no further comment at this time.”

All officials have microphones during the game which allow them to speak freely to one another, meaning that assistant referees Michael McDonough and Simon Long, and fourth official Michael Jones, should have been able to hear all conversations between Clattenburg and the players.

Allegations of racial abuse have marred English football for more than a year, with John Terry, the Chelsea captain, and Luis Suárez, the Liverpool striker, both having been banned by the FA over the past year. Terry was serving the second of his four-game ban yesterday.

Chelsea were also deeply unhappy with the refereeing performance yesterday of Clattenburg, with manager Roberto di Matteo accusing him of “ruining” the game after sending off two of his players and then allowing Manchester United a winning goal that was clearly offside. The main controversy surrounded Fernando Torres’s second booking, for a supposed dive, after there appeared to be slight contact with Jonny Evans, the Manchester United defender.

“I think it’s quite obvious, in the eyes of everybody, that the second yellow for Fernando wasn’t one, it was foul for us, and he probably should have booked Evans,” said Di Matteo. “The decisive goal was an offside goal. It’s a shame the game has to be decided in that manner.

“Surely when he [Clattenburg] is going to watch the images he’s going to realise that he made big mistakes. Fernando put the ball between Evans’ legs and was through and was kicked on his shin and he went down.

“We are massively disappointed that these key decisions were wrong. It always seems to be in favour of the opposition. It was a good game of football with two good teams and the officials ruined it.”

Di Matteo, his assistant first-team coach Steve Holland and goalkeeping coach Christophe Lollichon, were embroiled in a furious touchline row with Sir Alex Ferguson, the Manchester United, over the Torres dismissal.

Ferguson clearly had little sympathy and later claimed that Torres had got what he deserved.

“Being a striker myself, when I went through on goal, I would never think about going down,” said Ferguson. “He could have gone on and he chose not to. I thought he went down. I think Jonny may have just caught him a little bit but you can either carry on running, which he could have done, but he chose to go down. He could have carried on and scored.

“I would never have missed that chance. But he did go down, that’s the issue, and he has already been booked so it’s his own fault. We have had some shocking decisions down here.”

Ferguson also claimed that Clattenburg had booked Antonio Valencia for diving because he had already cautioned Mikel and did not want to send off the Chelsea midfielder. “I thought that it got a bit nasty,” said Ferguson.

Chelsea also launched an investigation into reports that a steward was injured by objects that were thrown on to the pitch following United’s winning goal.

Chelsea fans in the Matthew Harding stand hurled abuse and appeared to throw objects at the Manchester United players as they celebrated Javier Hernandez’s winner.

The steward, who was later taken to hospital, fell to the floor at the same time that the fans responded to the celebrations and needed approximately 10 minutes’ treatment by paramedics at the side of the pitch.

”We are looking at reports of objects that may have been thrown or incidents around the steward taking a fall,” a Chelsea spokesman said after the match.

”We are investigating all the incidents around that time.

”My information so far is that he slipped and fell, may have hurt his knee, and was being treated by the side of the pitch.

”He’s been taken to hospital.”

Hernandez gestured towards the pocket of home supporters after scoring the winner for United 15 minutes from time.

His captain Patrice Evra then tried to calm him down knowing the Mexican’s celebration was likely to anger the Chelsea fans.

More stewards were seen coming to the aid of their injured colleague, who was clearly in pain, before a team of paramedics ran around the edge of the pitch to help him.

After the game Chelsea cordoned off the section of the stand where the fans vented their anger at the United players.