Some 10 tourists have become ill in Amsterdam in the last few weeks after buying what they thought was cocaine from street dealers in the Dutch capital, the Parool reports on Tuesday.

The drug they are buying is actually heroin, the local health board said.

The board has issued English language leaflets warning tourists not to buy drugs from dealers on the street. One person, a 22-year-old British national, may have died taking heroin he thought was cocaine, the Parool reports.

‘Users who do not realise they are dealing with heroin have a higher risk of an overdose,’ a spokesman for the Jellinek addiction clinic told the paper.

The health board has distributed leaflets on the Leidseplein and Rembrantplein where the victims bought their drugs, but not in the red light district. Posters have also been hung up in budget hotels and clubs.