A Danish tourist has died in Tasmania after drinking tea made from poppies, in the third poppy-related death in the past three years.

Police say the man, 26, was found dead in his campervan by a fellow backpacker about 9:00am at Oatlands, 80 kilometres north of Hobart in the southern midlands.

Investigations suggest the man had been drinking tea made from poppy capsules.

Police say he and his travelling companion had stolen 40 poppy heads from a farm near Oatlands and used some of them to make a brew.

The Danish man drank it while his friend went out sightseeing.

The 26-year-old felt ill that night before he went to sleep.

Keith Rice from the Poppy Growers' Association says it is a tragedy for the man and his family but the risks are well-known.

"This just demonstrates the dangers that we've been saying for quite some time," he said.

"There are enormous dangers with going into our poppy crop and grabbing some brew and mixing it up."

Tasmania's deadly poppies

Tasmania is the largest legal producer of opium poppies in the world but some crops contain thebain, which if ingested in large quantities can cause convulsions and death.

Ronnie Voigt from Tasmania's Drug Education Network says poppy tea is popular in Europe but people may not understand that the Tasmanian variety can be lethal.

"It had been seen in the past to be a relatively safe way to get high but poppies that are used for poppy tea are not the same as used in Tasmania, so poppies have become a bit of a gamble," she said.

Ms Voigt says targeted messages may be needed to avoid further tragedies.

"It certainly could mean that we change our messages on our website or we need even further levels of education that may mean some level of response to those coming into the state and that could be those coming from interstate to Tasmania or coming from overseas."

It is the third poppy-related death in the past three years.

In 2012, a teenager died from morphine toxicity after he and others stole poppies from a farm.

Another person died in similar circumstances the year before.