Peruvian police say they will deport five tourists and prosecute another after they allegedly damaged stonework and defecated among the ruins at Machu Picchu, an Incan citadel that is one of South America's most renowned tourist attractions.

Key points: The tourists were from Chile, Brazil, France and Argentina

The tourists were from Chile, Brazil, France and Argentina The Temple of the Sun has limited access for tourists in order to preserve the site

The Temple of the Sun has limited access for tourists in order to preserve the site Machu Picchu is a UNESCO World Heritage site visited by more than a million tourists a year

Authorities said on Tuesday (local time) the tourists, from Chile, Brazil, France and Argentina, snuck into the ruins and caused a rock to fall from a wall of the Temple of the Sun, which damaged it.

One of the foreigners allegedly defecated inside the Incan city.

The tourists were arrested on Sunday when police and park rangers found them in a restricted area of the sacred Temple of the Sun, Agence France Presse (AFP) reported.

An Argentine man will remain in the country to face charges for "destroying Peru's cultural heritage" after he acknowledged a lead role in the vandalism.

According to AFP the tourists face at least four years in prison if they are found guilty.

The 15th-century Temple of the Sun has limited access for tourists in order to preserve the sacred and unique site.

Machu Picchu is at the meeting point of the Peruvian Andes and the Amazon Basin. ( Reuters: Enrique Castro-Mendivi )

It was built by the Inca for ceremonies giving offerings to the sun, which was a vital part of Incan life and culture.

The Temple of Sun was used to pay tribute to the sun, considered the creator of all things and the most important deity in the Inca empire.

Machu Picchu is a UNESCO World Heritage site visited by more than a million tourists a year.

It is set on a steep ridge made up of about 200 structures and is famous for its architecture and art covering 32,592 hectares of mountain slopes, peaks and valleys at the meeting point of the Peruvian Andes and the Amazon Basin.

The stonework has long intrigued visitors, but a spike in tourism has raised concerns about damage to the delicate site.

The United Nations has previously warned of urgent problems with deforestation, the risk of landslides, uncontrolled urban development and illegal access to the sanctuary.

Reuters