Leonardo da Vinci’s Self Portrait
The famous self portrait of Renaissance master Leonardo da Vinci is seen in critical condition in this handout photo released to Reuters in Rome, 26 June, 2012.

The most acclaimed self-portrait of Renaissance master Leonardo da Vinci is reportedly in a critical condition and may be irreparably damaged, restoration experts who conducted weeks of tests on the portrait concluded on Tuesday.

The test results have shown that the famous portrait of Leonardo da Vinci in red chalk, which shows him in his 60s, is deteriorating and any conservation would be more harmful to the sketch.

"I think we need to think very hard before we do anything to this very familiar face," Jane Roberts, Royal Librarian and Curator of the Print Room at Windsor Castle, told a press conference in Rome, according to a Reuters report.

According to conservation experts, the portrait, which is said to have been sketched in the early sixteenth century, has got blotches, stains and spots – a condition called Foxing in the art world for deteriorating objects.

Since restoration works can further damage the portrait, which measures 33.5 by 21.6 centimetres (13.2 by 8.5 inches), art experts are afraid to start any such effort.

"Because this is a masterpiece, prudence has prevailed. It's scary to deal with a work of art of this magnitude and uniqueness," Maria Cristina Misiti, head of Italy's Central Institute for Restoration and Conservation of Archival and Book Patrimony, added.

The self-portrait of the creator of some of world's most renowned masterpieces like Mona Lisa and The Last Supper is getting damaged beyond repair in an age when many rare art pieces and paintings have been restored.

Scientists at Nasa's Glenn Research Centre with their revolutionary method of using atomic oxygen to restore masterpieces have helped revive a number of paintings of historical and cultural importance that appeared to be irreparably damaged. Some of these include an Italian copy of a painting by Raphael called Madonna of the Chair, a fire-damaged painting by Jackson Pollack; a stained Andy Warhol painting Bathtub, and several smoke-damaged paintings at St Stanislaus Church in Cleveland, according to Nasa.

The final call to restore the self-portrait of Leonardo da Vinci also rests upon the scientists and the Royal Library of Turin, the restoration institute, according to Misiti.