Silvio Berlusconi, Italy`s prime minister, has been criticised after he broke a strict "no photographs" rule by posing with Russian President Dimitri Medvedev in front of The Last Supper, according to Telegraph.co.uk.
Mr Berlusconi posed in front of Leonardo Da Vinci`s 15th Century masterpiece for several minutes on Monday while the cameras flashed, despite prominent signs prohibiting flash photography.
Mr Medvedev, in Italy on holiday, visited the Last Supper at the Santa Maria della Grazie museum while on a tour of Milan with Mr Berlusconi.
Tourists who had booked a slot to view the work - which has a waiting list of three months - were held back to allow the politicians through.
Professor Ulberico Santa Maria, who works at the scientific department of the Vatican Museums, said: "There is no way I would have allowed flash photography in front of the Last Supper.
"Flash photography is not recommended at all for works of art because of the intense damage that can be caused - certainly photography is allowed but the conditions have to be strict controlled using filters.
"We do not allow any sort of flash photography in the Vatican museums - we have four million visitors a year here and if everyone took just one flash photograph the damage would be immense.
"The fact that the Last Supper is a mural painting and not a fresco makes it all the more fragile to something like flash photography, because of the organic material in the paint.
"This pigment is sensitive to flash photography and that`s why we do not allow it."
But Alberto Artioli, superintendent of works in the Italian city, dismissed concerns, saying the photo session had been short, and had come at the request of the Russian president.
He said: "I gave permission for three photographers to enter and take pictures. It was my responsibility, my decision and I authorised them because I did not see a problem.
"Flash photography can cause damage and ruin works of art, but in this it was just for a few moments. The photographers were quite far back and I really don`t see the problem."