Panorama's John Sweeney spoke to Daniel Domscheit-Berg, a former Wikileaks spokesman, about the whistle-blowing website and its founder Julian Assange.
Mr Domscheit-Berg, who has written a book about his time with Wikileaks and started his own competing site, told the programme in a wide-ranging interview that he and others expressed concerns about Mr Assange's leadership and the two parted ways last autumn.
Mr Assange, who is currently fighting extradition from the UK to Sweden to face allegations of sexual assault, did not grant Panorama's request for an interview. He denies the allegations against him and his hearing resumes Friday in London.
Panorama: WikiLeaks: The Secret Story, BBC One, Monday, 14 February at 2030GMT then available in the UK on the