A German collector voluntarily returned 18 archeological pieces to Peru, including a pre-Colombian copper funeral mask, the Peruvian Foreign Ministry said in a statement on Tuesday. The Peruvian consulate accepted the objects from the collector in Hamburg in 2004, but it took them two years to repatriate the pieces because they had to be authenticated and insured for shipment, the statement said. The valuable pieces, which were smuggled out of Peru, also include small sculptures and ceramics belonging to the pre-Incan Chimu, Viru and Mochica cultures. The collector considered it as his moral responsibility to restore this part of Peru's archeological heritage, which had been illegally removed from the country, said the statement. A large number of precious ancient objects of high historical and cultural value have been smuggled out of Peru in recent years. Earlier this year, the U.S. police seized 412 ancient Peruvian artifacts in an investigation into smuggling in Florida.