A man aged 36 is believed to have become the first person in Britain to die directly from cannabis poisoning.

Lee Maisey smoked six cannabis cigarettes a day for 11 years, an inquest heard. His death, registered as having been caused by cannabis toxicity, led to new warnings about the drug, which is due to be reclassified this month as less dangerous.

"This type of death is extremely rare," Professor John Henry, a toxicologist at Imperial College, London, said after the inquest at Haverfordwest, west Wales. "I have not seen anything like this before. It corrects the argument that cannabis cannot kill anybody."