A man of 'low intelligence' convicted of murdering a man by drowning him in the Thames has failed to convince appeal judges he was the victim of a miscarriage of justice.

Edward Doyle, 36, of Alice Smith Square, Littlemore, Oxford, befriended 'vulnerable' Sean Miles, who lived in sheltered accommodation, but often took advantage of him, London's Court of Appeal heard today.

When one of Doyle's friends accused Mr Miles, 37, of sexually assaulting her son in April last year, Doyle and two others attacked him and drowned him in the River Thames.

In his defence, Doyle said that, although he was present at the time, he did not actively participate in the assaults.

He was convicted of murder at Oxford Crown Court in April 2007 and sentenced to life in jail. His minimum jail term was set at 17 years.

Judge Saunders, sitting with Lady Justice Hallett and Mr Justice Teare, dismissed Doyle's application for permission to appeal against his conviction.

Terry McMaster, then 24, and Karen Fathers, then 35, of Alice Smith Square, Littlemore, were jailed for 15 and 14 years respectively in April last year for the murder.