Police said the incident took place in the Toshodaiji Kondo temple last week, which is in the city of Nara.

Speaking to CNN, officers said: "On the pillars to the side, the boy carved 'Julian' on a wooden pillar about 170cm above the ground with his nail."

The 17-year-old has been questioned on suspicion of violating the cultural properties protection law in Japan.

The monument's Golden Temple is also designated as a national treasure.

According to The Mainichi, a newspaper in Japan, a letter "J" was found 4cm long and 5cm wide - and the name "Julian" was 2.5cm long and 10cm wide on the pillar.

A Japanese tourist reportedly saw the new inscriptions being made and initially intervened, before alerting staff at the temple.

The boy reportedly said he had no intention of harming Japanese culture.

He will not be detained, but an investigation will continue.

A Buddhist temple, Toshodaiji Kondo was constructed in the 8th century and was designated as a UNESCO world heritage site in 1998.

It is part of eight monuments in the city known as the Historic Monuments of Ancient Nara.

It comes after a similar story in Rome last month where a tourist carved his name into the wall of the Colosseum using a key.

He was filmed carrying out the vandalism and was made to write an apology to the city's prosecutor.