London, March 28 : The restoration work on William Shakespeare's portrait, 100 years after his death, actually removed a superimposition that could have revealed an insight into the changing appearance of one of the world's greatest playwright.

When art conservators joined hands to restore two rare portraits of Shakespeare, they thought they were removing paint daubed on the canvases more than 100 years after the Bard's death to reveal "authentic" portraits beneath.

According to a report in the Independent, it has emerged that they were, in fact, wiping away priceless insights into the changing appearance of Shakespeare.

The images, which had been superimposed on both paintings, had actually been painted in Shakespeare's own lifetime, and showed how he looked as he aged.

The so-called "restoration" could now go down in art history as one of the biggest blunders on record.

A newly discovered picture of Shakespeare called the Cobbe portrait (painted when he was still living) and another version called the Folger portrait, were both irreversibly "cleaned up" in this way.

New research has revealed both portraits were probably altered during Shakespeare's lifetime, or within a decade or so of his death in 1616, while his friends and associates were still alive.

In the Cobbe portrait, the sitter was given a bouffant hairstyle, whereas in the Folger portrait, his hair at the front was replaced by a bald forehead.

The Cobbe work is believed to have been painted for the Earl of Southampton. It is possible the Earl may have wanted a more flattering image of the playwright.

The Folger portrait, on the other hand, may have been altered to reflect Shakespeare's appearance at the time of his death, six years after the original painting.

Rupert Featherstone, director of the Hamilton Kerr Institute in Cambridge, which undertook technical investigations into the Cobbe portrait, admitted that in hindsight, it was unfortunate conservators had removed the overpaint.

"We can no longer peer down a microscope to look at the physical evidence of the overpaint," he said. (ANI)