Italian fashion designer Roberto Cavalli has been charged with tax fraud, after prosecutors accused him of using $2.6 million written off in business expenses to refurbish his mansion.

Cavalli's lawyer, Alessandro Traversi, admits the money was used to build swimming pools, a gym and an airplane hangar at the designer's villa overlooking Florence underwent extensive renovations - but the designer insists the villa is essential to his business.

Cavalli's trial has been set for July 10, and some of his celebrity customers may be called as defence witnesses.