Street teams and "smart shops" in Amsterdam will start selling heroin test kits after three young British tourists died snorting a drug they thought was cocaine, Dutch media says.
"Starting tomorrow the test kits will be sold in 30 smart shops which will show the presence of heroin in drugs," the Amsterdam-based daily Het Parool said on Thursday.
"Tourists can also buy these test kits for two euros ($A2.68) from street teams," the paper added.
Three young British tourists – the latest two victims last week – recently died after snorting so-called "white heroin" which they thought was cocaine, bought from a street dealer in Amsterdam.
At least 17 other tourists also required medical treatment after taking the white heroin, which causes respiratory failure, police said.
The deaths and injuries prompted city authorities to put up electronic signboards saying: "Extremely dangerous cocaine is sold to tourists" while police have launched an intensive manhunt to track the dealer.
Amsterdam mayor Eberhard van der Laan praised the initiative to sell the test kits at the so-called "smart shops", which specialise in selling legal herbal "smart" drugs.
Van der Laan however on Wednesday warned that the test kits "should not be seen as fail proof".
"Users will clearly be told that the test is not a guarantee that the drugs they bought are safe to use," he said.
Van der Laan defended Amsterdam's famously tolerant approach to drug use, fending off criticism over the awareness campaign around the dangers of white heroin and how it impacted the city's image.
"Not doing anything would be bad for the city," the mayor 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.