U.S. ambassador killed in Libya attack 'said he was on al Qaeda hit list'
- Chris Stevens said he feared increasing threat of al Qaeda in Libya
- Raises yet more questions about why there was not security at consulate
- Comes amid claims that ringleader behind attack was former Guantanamo inmate handed over to Libya by America
- Sufyan Ben Qumu was classified as a 'medium to high' national security risk before his release from American custody