A vandal has daubed an image of a penis on a wall at a centuries-old Peruvian city recognised by Unesco as a World Heritage Site.

The man was filmed while spraying the graffiti on one of the original walls of Chan Chan, a pre-Columbian city 500km (300 miles) north of Lima that is visited by thousands of people a month.

Peru’s ministry of culture said the culprit showed “a grave disrespect toward our history and cultural heritage, as well as a violation of the regulations that protect archaeological heritage sites”.

Some Peruvians questioned how he was able to damage the wall unchallenged, while others said they were disappointed that the site was not better protected.

The video of the incident was widely shared on social media. The culprit could face up to six years in prison if caught.

Chan Chan was the capital of the Chimú kingdom before it fell to the Incas in the 15th century and it remains one of Peru’s most important archaeological sites.

Unesco describes it as the largest city in pre-Columbian America, stretching for miles and divided into several “citadels” by thick walls.

The spray paint attack comes just months after a man chipped the 12-Angle Stone, a famous Incan artefact in the city of Cusco.