A policeman has been suspended after allegedly calling a man a “nigger” during the London riots.

The officer, who sources named as Pc Alex MacFarlane of the Metropolitan Police, was apparently recorded by the suspect on his mobile phone as he was taken into custody.

The Guardian reported the officer told the 21-year-old black man: “The problem with you is you will always be a nigger, yeah?

“That’s your problem, yeah.”

The Independent Police Complaints Commission investigated and passed a file to the Crown Prosecution Service (CPS) after the man passed the recording to other police officers.

The CPS decided not to charge Mr MacFarlane or two other officers but tonight confirmed they would assess the file again after the man’s lawyers complained.

Grace Ononiwu, deputy chief crown prosecutor for the Crown Prosecution Service (CPS) London, said: “Lawyers for the complainant have written to the CPS and asked us to review our decision.

“I have considered the matter personally and directed that all of the evidence should be reconsidered and a fresh decision taken by a senior lawyer with no previous involvement in this matter.

“That process will be completed as soon as possible and is the procedure we often adopt when pre-action protocol judicial review proceedings are initiated.”

The Guardian reported that Mr MacFarlane also said to the man, who has not been named: “You’ll always have black skin colour.

“Don’t hide behind your colour, yeah,” adding: “Be proud. Be proud of who you are, yeah. Don’t hide behind your black skin.”

Another officer accused the man of being “a c*nt” and admitted strangling him.

Shortly before the recording ends, the man can be heard saying: “I get this all the time,” and telling the officer: “Make sure you do a lot with your sixty grand, ‘cos you’re not going to get it no more, bruv.”

He then tells the officer: “We’ll definitely speak again about this. It’s gonna go all the way, it’s gonna go all the way – remember.”

A Scotland Yard spokesman said: “We can confirm that the MPS received a complaint alleging a man arrested on August 11 2011 was subjected to discriminatory behaviour (racial remarks); assault and oppressive conduct/or harassment.

“These are serious allegations; any use of racist language or excessive use of force is not acceptable.

“The MPS’s Directorate of Professional Standards referred this case to the IPCC who are independently investigating.

“Following the alleged incident, three officers were the subject of a misconduct investigation. One of the officers has been suspended in relation to this matter pending the result of the IPCC investigation.

“One of the officers has been placed on restricted duties on an unrelated matter and another remains on full duties.”