Yale University has agreed to return to Peru thousands of Inca relics that were excavated at Machu Picchu. (Images courtesy of Yale Peabody Museum)

The relics were excavated from 1911-15 by a Yale history professor, Hiram Bingham.

During three trips to Machu Picchu, Bingham dug up thousands of objects, including mummies, ceramics and bones. (Image: Michael Marsland/Yale University)

In 2003 the artefacts went on display in a touring exhibition and the Peruvian government launched negotiations to get them back.

In 2006 Peru threatened to take the case before a US court, saying it had agreed to the objects' removal only on condition they would be returned.

Under the agreement Yale and Peru will co-sponsor a travelling expedition of the collection.

Yale will also act as an adviser for a new museum in Cuzco, close to Machu Picchu, where the exhibition will be installed after its tour. (Image: Michael Marsland/Yale University)

The Incas ruled Peru from the 1430s until the arrival of the Spaniards in 1532.

They built stone-block cities and roads, and developed a highly organized society that extended from modern-day Colombia to Chile.