The English football referee, Mark Clattenburg is facing allegations he used racist language towards a Chelsea footballer, and the case will now be investigated by the Metropolitan Police.
The issue is threatening to plunge English soccer back into another racism crisis, just as Chelsea captain John Terry is serving a four-match ban for racially abusing Queens Park Rangers defender Anton Ferdinand last year.
Chelsea have made a formal complaint that Clattenburg used "inappropriate language" towards two of their players in their home defeat to Manchester United but have not named names or gone into detail.
The Metropolitan Police confirmed it received a complaint from the chairman of the Society of Black Lawyers, Peter Herbert, and is now investigating.
The Football Association says Mark Clattenburg has been stood down for this weekend's games given the intense level of scrutiny.