Hussain's nom de guerre, Abu Sa'eed al-Britani, was found etched on the wall of a cell in the IS prison underneath the stadium at Raqqa. 49 tally marks were found underneath his name, indicating that he spent 49 days in the jail. Although it was reported that most captives of the prison did not survive their detention, the date beneath Hussain's name is 24 February 2016 - more than a full year prior to his actual disappearance and last activity on social media. Abu Sa'eed spent approximately two months in ISIS dungeons at that time, but made it out and participated in the Battle of Raqqa.