Police and the public prosecution office have released the names and photos of two of the suspects in connection with last weekend’s gold robbery at the Drents Museum in Assen.

It is not normal procedure in the Netherlands to reveal the identity of suspects who have not yet been charged for reasons of privacy. “It is not a decision we have taken lightly. We are looking for important works of art. Showing the images is necessary for the investigation,” a spokesman told broadcaster NOS.

Justice minister David van Weel said later the suspects had been told to come clean about the location of the treasure, or their photographs would be released.

All three suspects were picked up in Heerhugowaard, a town in Noord Holland not far from Alkmaar, where one of the cars used in the robbery had been stolen. One of the suspects is a woman but her identity has not been made public.

One of the three, Bernhard Z served five and a half years for robbery with violence while Douglas W has a record of drugs related offences, the AD reported.

Police say they began investigating the trio after finding a bag left behind in Assen which included articles of clothing. Police have also released photos of the clothing and the location, in an attempt to jog people’s memory.

In addition, they have appealed for information about a black Ford Transit van which may have been driven by one of the suspects.

The stolen objects, which included the priceless and ancient gold helmet of Cotofenesti and three golden arm bands, are part of Romanian national heritage and their disappearance has caused an uproar in the country.

So far, the director of the National History Museum in Bucharest has been fired over alleged irregularities over the export licence for the artifacts while Romanian prime minister Marcel Ciolacu has said Romania will claim “unprecedented damages” for the loss of the objects.

Police earlier issued a photograph of a fourth man they want to interview. He was filmed at a DIY store in Assen two days before the heist.