A police officer suspended following the death of Ian Tomlinson during G20 protests has been questioned on suspicion of manslaughter, the Independent Police Complaints Commission has said.
He was questioned after a second post-mortem examination found that Mr Tomlinson died from an "abdominal haemorrhage" and not a heart attack as first thought.
An IPCC spokesman said: "Following the initial results of the second post-mortem, a Metropolitan Police officer has been interviewed under caution for the offence of manslaughter as part of an ongoing inquiry into the death of Ian Tomlinson."
Pathologist Dr Nat Cary, who carried out a second post-mortem at the request of the IPCC and Mr Tomlinson's family, rejected the conclusions of the first.
He accepted there was evidence that Mr Tomlinson suffered hardening of the arteries in his heart, but found it was not serious enough to kill him.
In a statement, a spokesman for City of London Coroner's Court said: "Dr Cary's opinion is that the cause of death was abdominal haemorrhage. The cause of the haemorrhage remains to be ascertained. Dr Cary accepts that there is evidence of coronary atherosclerosis but states that in his opinion its nature and extent is unlikely to have contributed to the cause of death."
The first post-mortem, carried out by Dr Freddy Patel, concluded that Mr Tomlinson died from coronary artery disease.
The statement said: "The opinions of both consultant pathologists are provisional and both agree that their final opinions must await the outcome of further investigations and tests. These are likely to take some time."
A spokesman for the Metropolitan Police said the force was co-operating fully with the IPCC and would "proactively" give it any relevant information.
Lindsey German, convener of the Stop The War Coalition, said: "This news is very disturbing and emphasises the need for a full and open public inquiry into recent aggressive policing of legal protests."
