Scotland Yard is facing another case of alleged racism after a black firefighter claimed he was assaulted and tasered by a group of police officers because of his skin colour.

Edric Kennedy-Macfoy, 28, also says he was insulted and arrested without good cause when he went to assist the six policemen while they were dealing with a disturbance last year.

The firefighter, who was off duty at the time of the alleged incident, has lodged an official complaint against the force which is being investigated by both the MPS Directorate of Professional Standards and the Independent Police Complaints Commission (IPCC).

It is the latest in a wave of race related allegations made against Metropolitan Police officers which are being probed by the two watchdogs.

Mr Kennedy-Macfoy claims he was driving through Harrow in north London during the early hours of September 4 last year when he spotted a youth throw a rock at a police van.

He says he then stopped his car and approached a group of officers, who were dispersing a group of partygoers from a property in Harrow View, to inform them.

However, the firefighter claims he was insulted by the policemen, which included an inspector, sergeant, detective constable and two constables from Harrow borough, before being detained without good cause.

Mr Kennedy-Macfoy also claims he was assaulted during his arrest before being tasered.

He was later charged with obstructing police, but found not guilty following a trial at Brent Magistrates' Court in February.

The firefighter originally issued a complaint against the six officers shortly after the incident.

But the force did not launch a misconduct investigation because criminal proceedings against Mr Kennedy-Macfoy were on-going.

However, his solicitor sent a further complaint letter outlining the precise details of the alleged incident last week.

A Met Police spokesman confirmed officers had shut down a noisy party of more than 200 people on the day of the alleged incident.

"Some of those attending became hostile towards police and threw bottles and bricks at officers. Four police officers received minor injuries caused by missiles thrown at them," he added.

"A man arrived at the scene by car and approached officers on the cordon. He was subsequently tasered. He did not require medical treatment."

The force confirmed it had received a complaint against the conduct of six officers during the incident.

It alleged that "officers arrested and detained a 28-year-old man without good cause, assaulted him during the arrest, that the officers were insulting and the way in which he was treated was motivated by factors relating to race", the Met said.

The Met spokesman confirmed the MPS Directorate of Professional Standards is investigating the incident, which was also automatically referred to the IPCC as a taser was discharged.

The Met said it was taking the allegations "extremely seriously".

None of the officers, which also included a constable from the Diplomatic Protection Group and officers from black and ethnic backgrounds, have been suspended or restricted.

There are now 12 separate allegations of racism by Met officers under investigation by Scotland Yard and the IPCC.

They include the case of Pc Alex MacFarlane, 52, who will face criminal charges after being accused of racially abusing a suspect during last summer's riots. The alleged incident was recorded on a mobile phone. He will appear before magistrates in May charged with a public order offence.