Six Metropolitan Police officers have been suspended or placed on restricted duties following allegations of ill-treatment after a police raid.

The Independent Police Complaints Commission (IPCC) is investigating the Enfield-based officers' conduct, according to Scotland Yard.

A man has claimed his head was put down a toilet which was then repeatedly flushed during a drugs raid last year.

London Mayor Boris Johnson said the allegations were "extremely serious".

The Met said the allegations raised "real concern".

But they said they could not comment on the exact nature of the complaints.

Internal investigation

The raid on which the allegations are centred took place in November last year, during which five people were arrested.

BBC crime correspondent Ben Ando said the allegations did not concern "waterboarding" techniques - previously used by the CIA to interrogate terrorism suspects - as some newspapers had earlier claimed.

Water-boarding is aimed at simulating the sensation of drowning. It involves detainees being stretched on their backs or hung upside down, with a cloth pushed in their mouth or plastic film placed over their face before water is poured onto the face.

A Scotland Yard spokesman said a police employee had raised concerns about the conduct of a number of officers, during an internal investigation into allegations of mishandling of property.

"The Met's Directorate of Professional