The bodies of the two unnamed men, aged 20 and 21, were found in a hotel in southern Amsterdam on Tuesday, less than a month after another British tourist died in similar circumstances, said police spokesman Rob van der Veen.
“The men apparently died after sniffing white heroin which they may have thought to be cocaine,” Van der Veen told AFP.
Late last month a 22-year-old British tourist died in Amsterdam after taking so-called white heroin, a crystalline form of the drug that is usually injected.
At least 17 people have so far required medical treatment after taking the white heroin, Van der Veen said.
“White heroin looks like cocaine, is sold as cocaine and people think they are snorting cocaine.”
“The result is respiratory failure,” he said.
Many of Amsterdam’s tourists are drawn to its coffee shops where the sale of cannabis is tolerated, although hard drugs are illegal in the Netherlands.
White heroin is historically produced in southeast Asia’s “Golden Triangle” spanning Laos, Thailand and Cambodia and is generally purer and more expensive than brown heroin.