McLean disappeared last year

Roderick McLean was six years into a 21-year sentence when he went missing from Leyhill Prison last November.

A customs officer was killed during McLean's arrest, on board a boat laden with cannabis at sea off the Caithness coast in July 1996.

Avon and Somerset Police said a post-mortem has established McLean died from natural causes.

His body was discovered in bed at a property in Streatham Place, south London, on 14 January and identified by fingerprinting.

The case has now been referred to the coroner.

It had been thought he may have fled to South Africa where he had a home.

A police spokesman said: "A team of investigators were tasked with enquiries to establish both his whereabouts and if he had been engaged in any present criminality.

McLean had originally been held at Edinburgh's Saughton prison

"Enquiries will continue to establish where this man has been during his absence from prison."

Customs officer Alastair Soutar, 47, died when he was crushed between two boats in the operation to apprehend the 59-year old gang leader.

McLean was sentenced to 28 years in jail in 1997 for his part in the attempt to smuggle cannabis worth �10m from Spain to Scotland.

The sentence was later cut by seven years and he was transferred to Erlestoke Prison near Devizes and on to Leyhill in September 2002.

Mr Soutar's brother, Brian, said it was "appalling" McLean was allowed to be in an open prison.

Prison switch

"The circumstances of his death I know nothing about but certainly what does not add up to me is the basic facts surrounding how he managed to be in this holiday camp down in Gloucester rather than a high security Scottish prison," he said.

McLean had been moved to Leyhill, a minimum security Category D jail, from Saughton Prison, in Edinburgh.

He was being held as a Category B inmate at Saughton but prison chiefs decided he would not try to escape and he was transferred.

McLean's body was found at a flat in London

Leyhill has a long history of absconding prisoners and prison bosses came under fire following McLean's escape.

Home Secretary David Blunkett admitted in the Commons that sending a violent drug dealer to Leyhill had been a mistake.

Lothian and Borders Police refused to comment on speculation McLean was protected because he was a police informant.

It later emerged McLean was working as a caretaker at the flat where he died.

Ann Snowdon, the receptionist at Argo B&B Hotel said McLean had been working as a relief cover caretaker, answering the phone and the door, at the bed and breakfast and the flats next door.