Seven Mayan ancient artifacts will be heading to Guatemala after a representative of a longtime antiquities collector who was unsure of their origin turned them over to the FBI, which determined they were taken from the country illegally decades ago.

FBI officials said Friday that the pieces are more than a thousand years old.

FBI Special Agent Elizabeth Rivas says they were purchased innocently in the United States in the 1970s by a collector unaware that the party selling them dealt in looted antiquities.

A few months ago, a representative of the collector, who has since died, contacted the FBI saying that he couldn't establish provenance for the pieces. With the help of experts, the FBI was able to trace them to sites in Guatemala.

Guatemala plans to display them in a museum.