A 4,000-year-old temple filled with murals has been unearthed on the northern coast of Peru, making it one of the oldest finds in the Americas, a leading archaeologist said.

The temple, inside a larger ruin, includes a staircase that leads up to an altar used for fire worship at a site scientists have called Ventarron, said Peruvian archaeologist Walter Alva, who led the dig.

It sits in the Lambayeque valley, near the ancient Sipan complex that Alva unearthed in the 1980s. Ventarron was built long before Sipan, about 2,000 years before Christ, he said.

"It's a temple that is about 4,000 years old," Alva, director of the Museum Tumbas Reales (Royal Tombs) of Sipan, said after announcing the results of carbon dating at a ceremony north of Lima sponsored by Peru's government.

"What's surprising are the construction methods, the architectural design and most of all the existence of murals that could be the oldest in the Americas," he said.

Lambayeque is 472 miles from Lima, Peru's capital.

Discoveries at Sipan, an administrative and religious centre of the Moche culture, have included a gold-filled tomb built 1,700 years ago for a pre-Incan king.

Peru is rich in archaeological treasures, including the Inca citadel of Machu Picchu in the Andes.Reuters