A Greek prosecutor on Tuesday charged a former curator of the American J. Paul Getty Museum with knowingly buying an ancient artifact which had been illegally dug up and smuggled out of Greece 13 years ago.

The accusation that former antiquities curator Marion True illegally obtained a 4th-century BC golden wreath is the latest controversy surrounding acquisitions she made for the wealthy Los Angeles-based museum.

True resigned from her post in a whirlwind of publicity last year when Italian authorities charged her with conspiring to receive stolen antiquities.

In the Greek investigation, police raided her Aegean island villa earlier this year and retrieved what authorities say are dozens of unregistered ancient objects.

"True as well as two Greeks and two other foreigners have been charged with removing, accepting and distributing products resulting from criminal actions," a police source told Reuters.

"They are charged in connection with the golden wreath which was sold to a Getty representative in 1993 for $1.15 million."

The source said police believe an ancient Macedonian tomb was excavated some time between 1990-2 and it was then that the wreath was found and illegally removed.

Greece has disputed at least three other items in the Getty collection, two of which were returned in August as part of an agreement. In return, the Getty, among the world's richest art institutions, will receive other Greek antiquities on long-term loan and will be invited to co-host exhibitions of ancient Greek art.

Greece has pledged to crack down on the illegal trading of ancient artifacts. To ease museums' concerns, it has said it will only seek the return of objects proven to have been obtained through criminal actions.