Mother of British doctor Abbas Khan confronts Syrian delegation in Geneva screaming: 'Why did you kill my son?'

Video footage shows 'the sadistic nature of Assad regime', says Amnesty International's UK campaigns manager

Dr Abbas Khan who died while being held in custody in Syria. (PA)

The mother of British doctor Abbas Khan, who died while being held in a Syrian jail, has confronted the delegation from Bashar al-Assad’s government to peace talks in Geneva.

Video footage showed Fatima Khan approaching diplomats and asking, in increasingly desperate terms, why her son was “killed”.

As the delegates walk past ignoring her, Ms Khan screams: “For God’s sake tell me why you killed my son. He was a humanitarian aid worker. He wasn’t a fighter, he was a humanitarian aid worker.

“Don’t you have hearts?” asks Ms Khan. “Don’t you know who is a humanitarian aid worker and who is a fighter?”

An orthopaedic surgeon from London, Dr Khan, 32, was captured by the regime in November 2012 after he travelled to Aleppo to help victims of hospital bombings.

He was on the verge of being released in December when his family were told of his death, described by David Cameron as “a sickening and appalling tragedy”.

While the Syrian regime claim Dr Khan committed suicide, his family say he was the victim of a political murder.

After seeing the footage of Fatima Khan’s appeal today, Amnesty International’s UK campaigns manager Kristyan Benedict said it showed how the country’s government was “totally callous”.

He tweeted: “You can see the sadistic nature of the Assad regime in that short clip. The woman is desperate for answers and closure… they ignore her.”

Earlier, Syrian opposition leader Ahmad Jarba wrote on the social media site that he had “just had a meeting with Fatima Khan… [who is] in Geneva to get answers why the regime killed her son”.

He said: “I see Fatima like my mother and Dr Khan is like my brother, I appreciate the service of Fatima to raise the voices of the children in Syria.

Fatima Khan, mother of Abbas Khan, is comforted by her son (Stefan Rousseau/PA)

“In our meeting I promised to keep fighting against the regime for her and all the innocent people inside Syria. I told her, we know this regime very well. This regime kills innocents with impunity whether they are Syrian or British.

“I offer my deepest condolences to Fatima and her children who I met earlier in the week. Thousands of Syrians suffer their same tragedy every day. We will not rest until we get justice for all innocents who the regime continues to kill with impunity.”