Cinzia Parnigoni says she became "friends" with the statue

Franca Falletti, director of the Accademia Gallery in Florence where the statue is housed, said the cleaning would be finished by late May.

The controversial restoration - to remove grime and sulphate deposits - drew criticism from some art lovers.

The process, which uses distilled water to clean the statue, comes ahead of the statue's 500th anniversary.

Restorers have so far removed more than two thirds of the dull patina which had been obscuring the statue.

The Michelangelo masterpiece attracts more than 1.2 million people every year.

Critics unhappy

But work will continue after the clean-up, after checks revealed stresses in the ankles of the statue, which weighs more than six tonnes.

Some critics, such as Columbia University's James Beck, were unhappy with the plans to renovate the statue, saying the methods used would harm the famous statue.

I made friends with this statue Restorer Cinzia Parnigoni

The restoration got off to a bad start when expert Agnese Parronchi, quit last year rather than use techniques she said would harm the statue. She was replaced by Cinzia Parnigoni.

Some of the restoration has included chipping away sulphate deposits from previous clean-ups, and filling in tiny holes which had collected dirt.

"Working in an already poisoned climate wasn't ideal, but because of my conviction that the method I had to work with was the right one, I had no doubt," she said about taking over from Ms Parronchi.

Ms Parnigoni has spent the last six months applying a mud and cellulose pack on to the statue.

"I made friends with this statue," she said.

"The restoration has given uniformity and continuity back to the surface," Parnigoni told the news conference.

"I think it's a real improvement."