By Sarah Rainsford
BBC News, Istanbul
The Turkish government has sent a medical team to imprisoned Kurdish separatist leader Abdullah Ocalan, amid claims he has been poisoned.
Abdullah Ocalan remains a powerful symbol of defiance for Kurds
Last week, lawyers acting for Mr Ocalan produced results of laboratory tests on his hair which appeared to show high levels of toxic metals.
The justice ministry has dismissed the claims as a lie.
Mr Ocalan has been in prison since his capture in 1999. He is serving life for leading the PKK separatist rebel group.
The justice ministry has sent three experts to examine Mr Ocalan - including a toxicologist and a psychiatrist.
Justice Minister Cemal Cicek has made the government's position clear. He said the claim that Mr Ocalan had been poisoned was a lie.
If Turkey had ever seen that as an option, he said, it would have happened long ago. Turkey is a state based on the rule of law, he stressed.
Mr Ocalan was found guilty of treason in a Turkish court for leading the PKK in its armed campaign for an independent Kurdish state.
More than 30,000 people have died in the conflict.
Last month the Council of Europe ruled he was not entitled to a retrial.
The Turkish government maintains the allegation he has been "systematically exposed" to toxins while in prison is an attempt to revive international interest in his case.
But the claims have sparked a number of small protests by Kurdish groups in Turkey and abroad.
Many Kurds see Abdullah Ocalan as a symbol of their struggle for greater political and cultural rights, some for the fight for independence.
Kurdish politicians here have warned of "very serious" consequences if allegations of the poisoning are true. They have called for an immediate, independent investigation.
The justice ministry is expected to make its findings public in the next few days.