An investigation is underway into allegations that referee Mark Clattenburg used racist language with Chelsea's Juan Mata and John Mikel Obi during a Premier League match last weekend, London's Metropolitan Police said Tuesday.

Mata, who scored one of Chelsea's goals in the 3-2 home loss to Manchester United, is a Spaniard. Obi hails from Nigeria.

The Society of Black Lawyers asked Scotland Yard to probe the claims against the 37-year-old Clattenburg, which were already the subject of an investigation by England's Football Association.

"Our information is that racist remarks were directed at John Mikel Obi and at Juan Mata. If so, that is wholly unacceptable in any circumstances," the society said in a letter to police.

The referee denied using any racist language during Sunday's match at Stamford Bridge in London.

Another Spanish player on the Chelsea roster, Oriol Romeu, said Tuesday that Mata did not directly hear the alleged inappropriate comments by Clattenburg, but had been told about them by a teammate.

The referee angered Chelsea fans on Sunday by expelling Branislav Ivanovic - on a straight red card - and Fernando Torres - with two yellows - after the home side had come back from a 2-0 deficit to tie the match.

The Premier League announced the Clattenburg will not officiate any matches in the coming weekend. EFE