American stand-up Mitch Hedberg died of an accidental drug overdose, the US media have reported.

The comedian died in a hotel room in Livingston, New Jersey, in March at the age of 37 while on tour.

Although he was originally believed to have died from heart failure, the state’s medical examiner concluded he was killed by ‘multiple drug toxicity’ – including cocaine and heroin.

He had long struggled with drugs and alcohol, and in May 2003 was arrested in Texas for possession of heroin.

In an article in Spin magazine, which revealed the findings of the medical report, comedy agent Maureen Taran said life on the road is difficult for a comedian.

‘It's a very lonely existence,’ she said. ‘If you aren't born with manic depression, you will have it after being in this business.’