Syria accused of torture and 11,000 executions

There is clear evidence that Syria has systematically tortured and executed about 11,000 detainees since the start of the uprising, a report by three former war crimes prosecutors says.

The investigators examined thousands of images of dead prisoners reportedly smuggled out of Syria by a defector.

One of the authors told the BBC there was evidence of government involvement. Damascus has denied claims of abuse.

The report comes a day before peace talks are due to begin in Switzerland.

The Guardian newspaper in the UK - which along with CNN first unveiled the report - says the release appears timed to coincide with the conference, opening in the resort town of Montreux, and continuing in Geneva two days later.

The talks are being seen as the biggest diplomatic effort to end the three-year conflict which has left more than 100,000 dead and millions displaced.

'Significant starvation'

The report was commissioned by Qatar, which supports Syrian rebels. It is based on the evidence of a defected military police photographer, referred to only as Caesar, who along with others reportedly smuggled about 55,000 digital images of some 11,000 dead detainees out of Syria.

He told investigators his job had been to take photographs of corpses, both to allow a death certificate to be produced and to confirm that execution orders had been carried out.

"There could be as many as 50 bodies a day to photograph which require 15 to 30 minutes of work per corpse," he is quoted as saying.

He did not claim to have witnessed killings or torture himself, which the investigators said gave weight to his testimony.

The photographs cover the period from the start of the uprising in 2011 until August last year.

All but one of the bodies shown were male. Investigators say most of the bodies were emaciated; many had been beaten or strangled. Some had no eyes, and some showed signs of electrocution.

One of the authors of the report, Prof Sir Geoffrey Nice, told the BBC's Newsday programme that the scale and consistency of the killings provided strong evidence of government involvement that could support a criminal prosecution.

Forensic pathologist Stuart Hamilton told Newsday that in the images that he saw, a large number of detainees were showing "evidence of significant starvation".

He said that many looked as if they had been bound or restrained.

"There were a large number who had been beaten. And there were a significant minority who had clearly been strangled," he said.

The Syrian government has not commented on the report, but has denied accusations of human rights abuses during the 34 months of the conflict.

The BBC's Paul Wood, who has visited Syria several times during the conflict, says claims of systematic and bureaucratic torture are the unifying story among the rebels.

The question is why President Assad will attend a conference intended to negotiate his exit from power if he could end up facing prosecution over the deaths - one reason why the peace conference is expected to fail, our correspondent adds.

Boycott threat

The Syrian government and the main exiled opposition group, the National Coalition, are due to send delegates to the one-day Montreux conference on Wednesday.

On Monday the UN secretary-general withdrew an invitation to Iran - a key ally of the Syrian regime, over its refusal to support the plan to form a Syrian transitional government, the basis of the conference.

The invitation to Iran had angered the US, while the National Coalition had threatened to pull out if the invitation was not rescinded. They have since confirmed they will attend.

It is unclear whether Iran will be able to join the talks two days later, when they move to Geneva.

Russian Foreign Minister Sergei Lavrov said on Monday that not inviting Iran "is of course, a mistake ... But it isn't a catastrophe".

The conference is the culmination of months of diplomacy. In May last year, Russian and the US agreed to try to bring both sides together.

Later, the UN Security Council called for a conference to implement the Geneva communique - a deal on a transitional government agreed at a UN-backed meeting in 2012.