One of three Thames Valley Police officers accused of unlawfully killing a motorist has been found not guilty.
Robin Goodenough died from heart failure
Robin Goodenough, 26, of Barton, Oxford, died from heart failure shortly after he was stopped by police in Oxford city centre in September 2003.
At the Old Bailey on Tuesday, Pc Paul Summerville was cleared of manslaughter and assault causing actual bodily harm.
But the jury could not agree on verdicts for Pcs John Shatford, 32, and Robin Shane, 31, who deny both charges.
The two officers may now face a retrial.
In a statement Thames Valley Police said: "It is extremely disappointing that the jury has been unable to reach a verdict in relation to two of the officers.
"Together with the family of Robin Goodenough, they have already waited more than two years for this case to come to court and for the matter to remain unresolved is highly regrettable.
"However, this was not a straightforward case and we appreciate that the jury did not have an easy job to do.
"It is now up to the Crown Prosecution Service to decide whether or not there will be a retrial."
Pc Paul Summerville's actions will now be investigated by Hampshire Constabulary to see if he breached any police regulations.
The court had heard how Mr Goodenough, who had been disqualified from driving, was spotted behind the wheel of his sister's car by officers in a transit van. The officers pursued him into a dead-end street.
He was punched in the face and pulled out of the vehicle so violently he landed on his chin, the jury was told.
Mr Goodenough's teeth were dislodged, the bone to which they were attached broken, his lips cut, with blood going into his throat affecting his breathing, jurors heard.
Within 10 minutes of the officers arriving at his car door, he was in cardiac arrest.