Steven Puaca, 38, from Lowestoft, Suffolk, was found guilty in November 2002 of murdering Jacqueline Tindsley, 55, in March of that year.

Mr Puaca's defence was that his girlfriend died after taking a drug overdose and suffering a fit.

Three Appeal Court judges said there was not enough evidence to support pathologist Michael Heath's conclusion she had been died of asphyxia.

The key ground of appeal at the Old Bailey in London on Thursday related to the evidence of the pathologist Dr Heath.

The court heard he is facing disciplinary proceedings in connection with two cases, including that of Mr Puaca.

He is very pleased, but he is also understandably sad that he has carried that stigma for three-and-a-half years Steven Puaca's solicitor

Dr Heath's believed Miss Tindsley died of asphyxia, but the judges heard that a number of other pathologists said there was no evidence to support that finding.

The judges will announce their reasons for quashing the conviction at a later date.

Lord Justice Hooper said: "For reasons which will appear in the judgment that we shall hand down later, in our view there was no evidence, independent of the medical evidence, which was sufficient to make a jury, properly directed, sure that the cause of death was that advanced by Dr Heath."

Mr Puaca's solicitor, Chris Brown, said afterwards: "He is very pleased, but he is also understandably sad that he has been accused of what he was accused of and that he has carried that stigma for three-and-a-half years."