Media playback is unsupported on your device Media caption Susana Mendonca reports: The doctor's mother was heard saying ''please give me my son back''

The brother of a British doctor who died while being held in custody in Syria has paid tribute to him at his funeral, describing him as "our star".

The service for Abbas Khan took place at Regent's Park Mosque in London.

Mr Khan was days from being freed when the Syrian government announced on 17 December he had committed suicide. His family believes he was murdered.

He was arrested after arriving in Syria to work in a field hospital in a rebel-controlled area in November 2012.

An inquest into the death of the 32-year-old from Streatham will open at Walthamstow Coroner's Court on Friday.

'Kindest and simplest'

At a packed funeral prayer service, his brother Shahnawaz Khan said: "Last night, I sat down to undertake the morbid task of writing a eulogy for my brother."

"My brother, to us, was our star - his star shone on our family."

Dr Khan was described by his brother as the "kindest and simplest man I've ever met".

Mr Khan spoke of "the evil that has taken him from us so cruelly" and said the family had been through "one of the most difficult times we have ever seen".

In a very distressed state outside the mosque, Dr Khan's mother wailed and, as people tried to comfort her, she told people not to aid her.

"Nobody help me, I love my son. I am the loser. I'm the failure," she said.

"I beg everybody. I touch everyone's feet. Please give me my son."

Image caption Dr Khan's body was returned to the UK on Sunday

Solicitor Nabeel Sheikh said the family were "grateful for all the support they have received from the public".

He said the idea of suicide was "inconceivable".

However, he added the Foreign Office had done "nothing more" than send Mr Khan's family a letter of condolence.

The Foreign Office said it was giving the family "privacy and space to grieve".

Following the funeral, the body of Dr Khan, who leaves behind his wife, a seven-year-old daughter and a six-year-old son, was taken to Ilford to be buried.

Dr Khan's body was flown back to London on Sunday and a post-mortem examination later took place.

Cameron letter

Orthopaedic surgeon Dr Khan entered Syria without a visa, and later told his family he was "accused of treating dying civilians, (women and children), which has been classed as an act of terrorism".

His family has revealed a letter in which Dr Khan talked of his optimism at being released, and his hopes of being home in time for Christmas.

Prime Minister David Cameron wrote to Dr Khan's mother Fatima on 20 December, calling his death a "sickening and appalling tragedy".

The Foreign Office has said the doctor had been "in effect murdered" by the Syrian authorities and at best his death was "extremely suspicious".

Officials said they had "consistently sought" consular access to Dr Khan and information on his detention, directly and through the Russians, Czechs and others.

But Dr Khan's brother, Shahnawaz, criticised the UK government for not doing enough to secure his brother's freedom.

He said the Foreign Office had treated his case as if he was a "wayward traveller in Dubai being caught drunk".

The Syrian government, meanwhile, has told Dr Khan's family it could send a team to Damascus to investigate his death. It also said it would share the findings of its own post-mortem examination with the family.