The police watchdog is investigating the death of the British reggae star Smiley Culture during a Metropolitan police raid.
Although it is unclear how Emmanuel was injured, investigators are understood to be looking into whether the wound was self-inflicted.
A Scotland Yard spokesman said: "As part of an ongoing operation, officers from the Metropolitan police service's serious and organised crime command attended a residential address in east Surrey to carry out an arrest warrant.
"While they were at the address, an incident occurred during which a 48-year-old man died. Officers from Surrey police attended the incident and it has been formally referred to the Independent Police Complaints Commission."
The IPCC confirmed that it was looking into the death.
Mike Franklin, IPCC commissioner for the south east, said: "We will be looking into the planning of the arrest, the way in which it was carried out and the actions of all the officers who were present at the time of the incident."
Emmanuel had appeared before magistrates charged with conspiracy to supply cocaine last September.
He shot to fame in the 1980s with songs such as Cockney Translation — an explanation of rhyming slang — and Police Officer, an autobiographical song of how he was caught in possession of cannabis but let off when the officer recognised him as a reggae artist.
In an interview with the Guardian last year, he spoke of his time in the music business and his musical legacy.
"Although I paved the way for people like the Streets and Dizzee Rascal, I left the music business because I wasn't rich."
Ricky Belgrave, the chairman of the British Association of Static Systems, said Emmanuel's death was a sad loss for British reggae.
"He was a lively personality and one of the first wave of UK talent like Maxi Priest, Tippa Irie and Aswad, to cross over to the mainstream," he said.
http://www.guardian.co.uk/music/2011/mar/15/smiley-culture-dies-police-raid