A controversial new book due this month is set to lift the lid on French first lady Carla Bruni-Sarkozy's 'secret life and lovers'.

The lawyers of Bruni-Sarkozy are bracing themselves for the release of the book, written by Besma Lahouri. The security around the book is tight and even the title has not been disclosed.

'It's a robust, anything-goes book which contains explosive revelations about everything from Carla's relationship with secret lovers to plastic surgeons,' telegraph.co.uk quoted a publishing source as saying.

'The principal story is about a fast-living adventuress with an obsession with wealth and fame. Nobody from Carla's camp has assisted with anything. This is a proper, unbiased investigation into a world-famous former model, pop singer and first lady,' the source added.

Lahouri, who also wrote a biography of French footballer Zinedine Zidane, is currently in hiding and security guards are said to be protecting his work, which is due in about two weeks.

Bruni-Sarkozy has had string of affairs with high-profile men including the English rock stars Mick Jagger and Eric Clapton.

According to a source at the Elysee Palace, any attacks on Bruni-Sarkozy, including in biographies, would be viewed 'very seriously'.

A spokesman for Flammarion publishers said the new biography is 'an investigation without co-operation and without bias'.