Britain accused Syria on Tuesday of effectively murdering a surgeon who was detained after volunteering to work at a hospital in the war-torn country and then died in jail.
Abbas Khan, a 32-year-old orthopaedic surgeon from south London, travelled to the northern city of Aleppo last year to help civilians but was captured by the Syrian regime.
His family said on Tuesday that the father-of-two had died in detention, just days before he was due to be freed and handed over to a British lawmaker.
Syrian officials reportedly said Khan had committed suicide, but British junior Foreign Office minister Hugh Robertson said the Assad regime was responsible.
"There is no excuse whatsoever for the treatment that he has suffered by the Syrian authorities, who have in effect murdered a British national who was in their country to help people injured during their civil war," Robertson told the BBC.