England football captain John Terry has been questioned in relation to allegations that he racially abused Anton Ferdinand, the BBC understands.
Terry, 30, who is also Chelsea's captain, denies aiming a racist slur at the QPR player in a game on 23 October.
The Metropolitan Police confirmed that a "30-year-old man was interviewed under caution on Friday 25 November. He was not arrested".
The Football Association is also looking into the incident.
Some members of the public claimed video replays from the match at Loftus Road showed Terry using racist language, while the FA said it had received a complaint.
Ferdinand has previously given a statement to the FA, saying he has "very strong" feelings on the matter, but will not elaborate until the FA inquiry has been concluded.
The FA's investigation into the allegation cannot be completed until the outcome of the police investigation.
In a statement following the game at Loftus Road, Terry described the incident as a "misunderstanding" and claimed that his accusers "have leapt to the wrong conclusions about the context of what I was seen to be saying".
He added: "I would never say such a thing - and I'm saddened that people would think so."