The man accused of selling white heroin to a number of tourists in mistake for cocaine may be freed because none of his victims can identify him, the Telegraaf says on Thursday.

The paper says the public prosecution department has questioned several tourists who bought the drug but they were unable to give clear statements.

Flip S, who is 42, turned himself in to police after photographs of security footage were shown on television. He has always maintained he did not know the drug was heroin.

Three British tourists died and some 20 people were hospitalised after they bought the drug, which they thought was cocaine.

Amsterdam city council took to using large matrix boards in popular parts of the city to warn tourists of the risks.