Madrid, Dec 3 (IANS/EFE) A truck carrying art works valued at 5 million euros ($6.5 million) was stolen last weekend near the Spanish capital, authorities said Thursday.

Security cameras at a warehouse in Getafe filmed three hooded men breaking in to steal the truck, a police spokesperson told EFE, adding that the keys had been left in the vehicle.

The truck was found empty Tuesday and police have made no arrests, the spokesperson said.

The only person questioned in the case so far is the truck’s driver, identified as a Romanian national, press accounts said Thursday.

Inside the truck were around 20 valuable pieces lent by galleries in Madrid and Barcelona to a gallery in Cologne, Germany. The art was on its way back to the Spanish galleries at the time of the robbery.

While the highest-priced works were insured, the truck was also carrying uninsured pieces, the press said.

Given that the keys were left in the vehicle and the robbers’ apparent knowledge of the truck’s cargo, police suspect the heist was carried out with help from an accomplice on the inside.

Among the works stolen is a sculpture by Eduardo Chillida (1924-2002) worth 800,000 euros (nearly $1 million), as well as pieces by Fernando Botero, Pablo Picasso, Antoni Tapies and Julio Gonzalez, the Spanish media said.