Thieves have long targeted Indonesian antiquities left over from the country's Hindu and Buddhist era. The objects - mostly statues and temple reliefs - are in demand by wealthy locals and collectors on the international market.
Syahroni said the thefts were uncovered after an ex-staffer at the museum told police of her suspicions. He said the 69-year-old curator told officers he stole them last year and replaced them with replicas made by local stonemasons.
The Buddhist statues dated back from the fourth century were sold for between US$3,500 (€2,352) and US$10,000 (€6,724), media reports said.
Officers seized the originals in a raid on the house of a wealthy businessman in the capital, Jakarta, Syahroni said.