A fifth person has been arrested as the investigation into the theft of a gold Romanian helmet and several armbands from a museum in Drenthe continues.

The new suspect is a 36-year-old man from Alkmaar, who was picked up at his home in the city on Tuesday morning.

No trace of the helmet has been seen since the heist at the Drents Museum in Assen in January.

A fourth person, a 26-year-old man from Heerhugowaard, was arrested in February, and two men and a woman were arrested in the same town at the end of January. Three of them remain in custody.

The latest suspect is not the person caught on security camera at a DIY store in Assen shortly before the robbery, police say.

The heist occurred in the early hours of a Saturday morning after an explosion shattered windows and caused damage to the museum buildings. The thieves made off with the golden helmet of Cotofenesti, crafted from almost pure gold and dating from 500 BC, along with three gold armbands.

The Romanian authorities have since criticised the Drents Museum for not having enough security measures in place. Camera footage of the heist shows three men breaking down the door following the explosion.