A drug addict died in Oxford from a heroin overdose just four days after leaving prison.

John-Paul Carter, 28, took a dose which six months earlier may not have killed him, but he apparently ignored a warning that his tolerance to the drug was lower because of his time off it in prison, Oxfordshire Coroner Nicholas Gardiner said yesterday.

Mr Carter was found dead in a room he had been put up in after being released from Bullingdon Prison, near Bicester, in February.

After examining his body, pathologist Dr Gareth Turner said: "He had two and a half times the amount of heroin usually found in fatal morphine overdoses. In my opinion, it was due to a morphine overdose."

Mr Gardiner read out evidence that Mr Carter, a schizophrenic, had been on medication for his mental health. He said that Mr Carter's health had improved, but he had been kept on the hospital wing of the jail until he was released on February 14.

In a statement, community psychiatric nurse Ben Ofori-Mensah said he took Mr Carter to Oxford City Council's homeless persons unit after his release and then to temporary accommodation in Iffley Road.

Mr Gardiner heard Mr Carter had used heroin for six years, had a history of self-harm, and had tried to kill himself three times.

Dc Stephen Clarke, of Cowley police station, found Mr Carter's body in his room on February 18. He said there was nothing suspicious about Mr Carter's death.

Recording a verdict of accidental death, Mr Gardiner said: "Mr Carter didn't understand or chose to ignore advice he had been given about his tolerance (to heroin)."