The mother of a British surgeon has demanded answers after accusing Syria of "killing" her son following his death in a Damascus prison.
The circumstances in which Dr Khan, a 32-year-old orthopaedic surgeon from London, died while in detention in Syria remains in dispute.
Speaking after his body arrived back in the UK Fatima Khan said: "I don't know why they killed my son and I want to ask why. Why on the release date they killed my son, I want answers. They are liars, every ministry is liars in Damascus."
David Cameron has written to the mother of a British doctor who died in custody in Syria, describing his death as "a sickening tragedy".
The mother of British doctor Abbas Khan, who died after 13 months in a Syrian prison, has accused the regime of "murdering" her son.
Relatives of British surgeon Dr Abbas Khan have said they do not understand what led to his death just days before he was due to be released