(Reuters) - The FBI has returned two 15th century world maps stolen from Madrid's national library this year.
The rare maps were found by an FBI agent working in the New York art world where they can sell for hundreds of thousands of dollars in auctions, police said.
They were some of 19 illustrations stolen in August by a Uruguayan man who walked into the national library posing as a researcher and tore pages out of books dating back to 1482.
The two maps handed over to Spain were taken from an edition of Ptolemy's Geographia, a compilation of second century world geography by Greek scholar Claudius Ptolemy.
The maps inspired Columbus to head west in search of India, only to land in the Americas in 1492, and only a handful still exist.
The robbery led to the resignation of the national library's director and prompted an international search for the thief and his 500-year-old treasure.
Cesar Gomez Rivero, the 60-year-old charged with the robbery, surrendered eight stolen maps to police in Argentina via his lawyer. The FBI said he is on the run in South America.
So far 11 of the maps have been recovered by police in the United Kingdom, Australia, Argentina, and the United States, the FBI said.