The Geneva public prosecutor's office said on Friday that it had returned the small, two-handled jug dating from the pre-Columbian Chancay period between the 12th and 15th centuries to the Peruvian embassy in Bern.

"It is priceless," Sophie Bernard, a spokeswoman for the office, told AFP.

Federal Swiss police discovered last year that a man born in 1981 and living in Geneva was trying to sell the archaeological artifact over the internet using a pseudonym, the prosecutor's office said in a statement.

The beige jug with its dark-lined motif had likely been found during "illegal excavations carried out in the valleys of Chillon, Chancay or Huara", to the north of Lima, it said.

The person who tried to sell the archaeological treasure would face charges for handling stolen goods and violating a law prohibiting the transfer of cultural objects, it added.

He could face up to five years behind bars, Bernard said.