Philip Muncey (37), of Crescent Road, Hunstanton, was found dead in bed at his home on March 19 by his father, John.

Mr Muncey told the inquest his son had a history of taking drugs but he believed he had been completely clear for four or five years. "Since then, I didn't think he had taken any. It was a complete shock," said Mr Muncey.

On the evening of March 18, Philip went to Cambridge on his motorcycle, which was nothing out of the ordinary. "He used to flit backwards and forwards to see friends and family," said Mr Muncey.

He came home and went to bed but at about 10.30pm told his mother he had been violently sick, which Mr and Mrs Muncey attributed to something he had eaten.

The next morning, because he had been ill and it was his day off, they let him lie in. About 1pm, his mother knocked on his bedroom door but received no response. Mr Muncey then went in and found his son had died.

He believed any overdose was an accident and Greater Norfolk Coroner William Armstrong said there was no question of Philip intending to harm himself.

He was inclined to the view that Philip had not been regularly and persistently taking heroin in recent years. After a period of abstinence, he may for some reason have gone back to using it at a time when his body had lost its tolerance and a small amount would have been sufficient to cause his death, said Mr Armstrong.