The Russian Acting president, Vladimir Putin, has asked the security services to ensure the safety of a Russian journalist with the American-funded Radio Liberty, Andrey Babitsky.

He went missing in Chechnya earlier this year after he was arrested by the Russian authorities.

They said they had exchanged him for Russian soldiers captured by Chechen rebels, but the Chechens denied this.

Mr Putin, who was head of Russia's security services, said he was in constant contact with the general prosecutor's office and the security services over the case.

From the newsroom of the BBC World Service