Acting for Ocalan, Greek lawyer Yiannis Rahiotis has filed a compensation claim of 20,100 euros (25,500 dollars), alleging that the Greek state betrayed him after offering assurances of safety, the source said.

On the run from Turkish agents, Ocalan hid in Athens for two days in January 1999 before being helped by Greek intelligence to flee to Kenya, where he was arrested by Turkish agents with the aid of US intelligence and condemned to death after a trial in Turkey.

The sentence was later commuted to life in prison as Ankara abolished capital punishment as part of reforms sought by the European Union, which Turkey hopes to join.

Three Greek ministers were sacked over the affair at the time and 13 people including Ocalan were later put on trial over his illegal entry, which proved a diplomatic disaster for Greece.

Ocalan is the head of the Kurdistan Workers Party (PKK), which is considered a terrorist organization by Ankara and much of the international community.

The PKK took up arms for self-rule in Turkey's mainly Kurdish southeast 24 years ago, sparking a conflict that has claimed some 44,000 lives.