The BBC has voiced growing concern for the safety of reporter Urunboy Usmonov one week after he was detained by security services in the Central Asian country of Tajikistan.
The corporation claimed Usmonov has been denied access to his family, colleagues and lawyer since he was detained on 13 June.
It has been joined in calls for his immediate release by the British and American Embassies in Tajikistan but there has so far been no response from authorities.
Reports published in the country on 18 June accused the BBC correspondent of being a member of banned Islamist group Hizbut-Tahrir.
In today's statement the corporation said: 'We strongly reiterate that these allegations are unfounded and the BBC sees them as a serious threat to professional journalism and to freedom of expression in Tajikistan.
'Urunboy Usmonov as a BBC journalist is expected to cover all sides of any story and in the course of his work it is only natural that he would meet and interview people representing all shades of opinion.
"It is vital for all journalists to be able to report freely on any organisation without fear of harassment and intimidation.
"We continue to be highly concerned for Urunboy's safety. He suffers from a serious heart condition and has requested further medical attention."
The head of the BBC's Central Asian service Hamid Ismailov said the grip of the country's security services was so strong 'that even high-ranking officials in local government couldn't clarify the situation, let alone assist in his release".
The BBC statement continued: 'His [Ismailov ] family have expressed deep concerns about his health and possible maltreatment in the detention centre.
'Our thoughts are with Urunboy and his family, and we appeal to everyone with influence over this situation to redouble their efforts to secure the immediate release of the BBC reporter Urunboy Usmonov by the Tajik authorities."