The trial of Israel's ex-president Moshe Katsav on several accounts of rape, sexual harassment and indecent acts opened on today only to be adjourned until September.

Katsav arrived at the Tel Aviv court at the start of the high-profile trial vowing to fight for his innocence on all the charges, which forced him to step down from office two years ago.

moshe katsav ex israeli president sexual rape case 140509 "We are starting today a tough and long struggle to clear my name and I promise once again that I will emerge innocent," the 63-year-old Iranian-born father of five told reporters.

The trial - in which at least 56 witnesses have been called to testify - opened with a 20-minute session where Katsav pleaded his innocence after which the district court judge adjourned the proceedings until Sept 1.

Katsav has been indicted on two counts of rape, forcible indecent assault and abuse of power against an employee at his office while he was tourism minister in the 1990s, the justice ministry said.

He is also accused of sexually harassing at least one female employee while he was president, and of obstruction of justice, it said.