"Vanunu was detained in Jerusalem last night," said police spokesman Micky Rosenfeld.

"He was arrested for talking with a foreigner," Rosenfeld told AFP.

YNet News said Vanunu was arrested at a Jerusalem hotel during a meeting with a Norwegian.

Vanunu was jailed in 1986 for disclosing the inner workings of Israel's Dimona nuclear plant to Britain's Sunday Times newspaper. Since his release in 2004, he has been detained several times for violating the terms of his parole which ban him from travel or contact with foreigners.

Israel is widely believed to be the only nuclear power in the Middle East, with around 200 nuclear warheads, but has a policy of neither confirming nor denying that.

The Jewish state has refused to sign the nuclear Non-Proliferation Treaty or allow international surveillance of Dimona, in the southern Negev desert.

Vanunu became an international cause celebre during his time in prison. At home, he is still widely reviled for converting to Christianity shortly before he was kidnapped in Italy and jailed after being covertly shipped back to the Jewish state.