The wife of imprisoned Russian activist Ildar Dadin has spoken to the BBC about his claims to have been tortured in prison.

Anastasia Zotova spoke to Sarah Rainsford after visiting Mr Dadin for the first time since the allegations surfaced earlier this month.

Mr Dadin said he had been beaten, and threatened with rape when he was transferred to a prison in north-western Russia in September.

A Kremlin spokesman said the case required "close attention" but the prison service has stressed that so far medical checks have not revealed any injuries.