A new door covered with special humidity-resistant paper has been installed in the cell for better ventilation, and Ocalan will have more time for his daily walk, the newspapers Hurriyet and Milliyet said.

Ocalan, founder of the outlawed Kurdistan Workers' Party, considered a terrorist organisation by Ankara and much of the international community, was transferred in November to another cell in the Imrali island prison.

He has been serving a life sentence there since 1999.

Following a recommendation from the Council of Europe's anti-torture committee, he will also be able to spend more time with other prisoners.

Ocalan had complained to lawyers that the new conditions were "worse than before", sparking major demonstrations in the majority Kurdish southeast of Turkey, resulting in three deaths.

On 11 December the constitutional court banned the main pro-Kurdish party in Turkey, the Democratic Society Party.