The Director of the Vatican Museums has warned that the sweat emanating from throngs of tourists is threatening precious works of art in the Sistine Chapel.

As many as 20,000 visitors a day file into the chapel in Rome to catch a glimpse of masterpiece by Renaissance greats Raphael, Bernini, Botticelli and Michelangelo, whose Last Judgement is among the chapel’s finest treasures.

Speaking to La Repubblica newspaper, Antonio Paolucci said the priceless works would suffer “serious damage” unless the chapel’s climate control system was updated.

"In this chapel people often invoke the Holy Spirit. But the people who fill this room every day aren't pure spirits," Paolucci told the newspaper.

"Such a crowd ... emanates sweat, breath, carbon dioxide, all sorts of dust.

"This deadly combination is moved around by winds and ends up on the walls, meaning on the artwork."

Paolucci has ruled out introducing a filtration system similar to the one installed at Santa Maria delle Grazie convent in Milan, where Leonardo da Vinci’s The Last Supper is housed.

Visitors there are required to walk through the filtration system prior to viewing the work and only 25 can be permitted in any 15 minute period.

Paolucci told Agence France-Presse that such a measure would “not be right” for the Sistine Chapel.

“The means offered today by science and technology are potentially endless,” he told the news agency. “The money, we will find it. No one shirks for the Sistine Chapel.”