By Simon Watts
BBC News, Miami
Customs officials in Florida have seized more than 300 ancient Peruvian artefacts smuggled into the US.
The artefacts date from before the arrival of the Spanish conquerors
The artefacts include a clay vessel thought to be 3,500 years old.
The operation was one of the largest of its kind and was launched after officers received a tip-off. One person has been arrested.
This pre-Columbian collection will now be returned to Peru, but customs officers say many other artefacts have not been found.
The 322 objects recovered in Florida include decorated pottery, burial shrouds and gold jewellery - all dating from civilisations which flourished hundreds of years before the arrival of the Spanish conquerors.
The officer in charge of the investigation said the items were the thread of a nation rich in cultural heritage, not souvenirs to be bought and sold.
The objects were probably looted from Peruvian sites and museums
Unfortunately, that is exactly what these professional smugglers were hoping to do.
Private US collectors are willing to pay thousands of dollars for stolen cultural treasures.
Customs officers say these objects were probably looted from poorly guarded sites and museums in Peru, before they ended up in the hands of the gang.
The officers think that because of its proximity to Latin America, south Florida has become a major transit point for the trade in stolen artefacts.