Israeli police have arrested nuclear whistleblower Mordechai Vanunu for violating a ban on him speaking to foreigners.

Mr Vanunu was jailed as a traitor in 1986 and served an 18-year sentence after discussing his work as a technician at Israel's Dimona nuclear reactor with a British newspaper.

The interview led experts to conclude the facility had produced fissile material for as many as 200 atomic warheads.

After his release from jail in 2004, Israeli defence authorities barred Mr Vanunu from travelling abroad, alleging he has more details on the Dimona atomic reactor to divulge.

The restrictions, upheld by Israel's Supreme Court, have been condemned by international human rights groups.

Mr Vanunu denies he poses a security risk but says he will pursue anti-nuclear activities and wants to live abroad.

In 2007, Mr Vanunu was sentenced to six months in jail for violating the ban on contact with foreigners.

Israel neither confirms nor denies having the Middle East's only atomic weapons under a policy of "strategic ambiguity" billed as warding off enemies while avoiding arms races.

Mr Vanunu, a Jewish convert to Christianity, argues that by refusing international inspections at Dimona, Israel inflames regional tensions and risks a "second Holocaust".

He has also said the Jewish state has no right to exist and there has been little public sympathy for him in Israel.

- Reuters