Vanunu was forced to post bail of 50,000 shekels (11,500 dollars) and ordered to remain at his residence at St George's Anglican cathedral in east Jerusalem where he has been living since his release in April.

As part of the terms of his release after serving an 18-year sentence for lifting the lid on the inner workings of the Dimona nuclear plant, severe restrictions were placed on his movement.

Vanunu converted to Christianity shortly before he was arrested, fuelling accusations among Israelis that he is a traitor to the Jewish state.

Jerusalem police spokesman Shmuel Ben Ruby said Vanunu had been arrested while wearing a Father Christmas hat while travelling in a vehicle that was marked up as a press vehicle.