Four Thames Valley Police officers have been arrested following the death of a motorist who had been stopped in Oxford.

The officers were taken to four separate police stations in Hampshire for questioning by detectives from Hampshire Constabulary, who are investigating the incident. They were released on police bail until December 2.

The names and ranks of those involved have not been disclosed.

The Police Complaints Authority (PCA), supervising the inquiry, refused to specifiy the nature of the questioning. Thames Valley Police refused to say if the four had been suspended from duty.

Robin Goodenough, 26, who had learning difficulties and a severe stutter, was pulled over by officers in Alma Place, east Oxford, because they thought he had committed an offence. His sister, Susan Williams, 28, who was with him in the Vauxhall Astra when he was stopped early on Saturday, September 27, said she heard "weird noises" coming from him.

Police became concerned and called an ambulance. He stopped breathing and was pronounced dead at the John Radcliffe Hospital, Oxford.

Mr Goodenough's mother Glenys rang the Oxford Mail within hours of his death to ask reporters to look into what happened.

She said: "I am just relieved. Hampshire Police have really worked hard and I admire them." Mr Goodenough's brother Thomas, 31, said: "We can't have the funeral at the moment, so we can't lay him to rest, which is so cruel. We are hoping that maybe now we can grieve, but we are still in shock.

"This is something you don't get trained for in life and we are trying to deal with it as best we can."

Chief Supt David McWhirter, Oxford Area Commander, said the arrests were part of the preliminary stage of the investigation and should not be seen as a "presumption of guilt".

He said: "We await the decision of the PCA and Crown Prosecution Service as to the final outcome."

Mr Goodenough had been arrested numerous times for driving offences and had been released from Bullingdon Prison just hours before his death for driving while disqualified.

Tests are still being carried out to determine the cause of Mr Goodenough's death.

An inquest was expected to open on October 16.