The death of a Danish backpacker who drank a brew of tea made from poppies has prompted a warning from a Tasmanian coroner about the dangers.

Jonas Havskov Pedersen died on his 26th birthday in February 2014 as a result of morphine intoxication after drinking poppy tea.

He was on a working holiday at the time he climbed a poppy field fence somewhere between Jericho and Oatlands and took some poppy heads.

Mr Pedersen began to vomit several hours after drinking the tea and his travelling companion said he looked "scared" and did not "look right".

Both men eventually went to sleep in the van they were travelling in and the alarm was raised by his companion the next day when he could not be woken.

He was taken to a medical centre at Oatlands where a doctor concluded he had died.

Coroner Olivia McTaggart found Mr Pedersen had been aware of and understood signs prohibiting people from entering poppy fields.

But she said it was unknown whether he was aware of the differing varieties and varying strength of the poppies grown commercially in Tasmania.

The consequences of ingesting commercially grown poppies were "unpredictable" and Mr Pedersen's death demonstrated the dangers of it.

The coroner said there had been several deaths in Tasmania involving young people removing poppy heads and she did not feel it was necessary to make any new recommendations.