The British government has claimed only one civilian has been killed by RAF bombing in Syria and Iraq that killed and injured more than 4,000 Isil fighters.
An estimated 4,013 militants have died in four and a half years of bombing, with 302 surviving with injuries, according to new, disputed Ministry of Defence (MoD) figures.
The figures, covering a period from September 2014 to January this year, were released on Thursday following a Freedom of Information request by the campaign group Action on Armed Violence (AOAV).
The US-led coalition, of which the UK is the second-biggest contributor, say they conducted a total of 33,921 strikes between August 2014 and end of January 2019, and at least 1,257 civilians have been unintentionally killed by during this period.
It is understood the MoD has carried out more than 1,700 strikes during its campaign on the cities of Raqqa and Mosul, reporting only the one civilian casualty in March 2017.
The man died after crossing into the strike area on a motorbike moments before the blast, the MoD said. Airwars, an organisation that tracks civilian deaths, believes between 7,500 and 12,077 non-combatants are likely to have died over the same period – 10 times higher than the official figures.
The one civilian casualty the UK has said it was responsible for would amount to just 0.09 per cent of all of the coalition’s civilian casualties.
“The RAF’s claim of a ratio of one civilian casualty against 4,315 enemies must be a world record in modern conflict,” Iain Overton, executive director of AOAV, said of the findings.
“Yet few conflict experts believe this to be true. To them, it is clear that far more needs to be done by the UK to improve transparency surrounding civilian casualties from airstrikes. Its coalition partner the US has committed to such, so why not the UK?"
Air strikes have flattened cities across Syria and Iraq. Bodies are still being pulled from the ruins of Mosul, Iraq’s second city.
Local morgues have reported to have received as many as 9,000 to date. Mass graves are still being discovered in Raqqa, the former capital of Isil’s “caliphate” in central Syria, where victims of raids were dumped.
Lydia Wilson, research fellow at Oxford University’s Centre for the Resolution of Intractable Conflict, said it is "absurd" to suggest only one civilian was killed while whole cities were reduced to rubble.
"I would ask how the RAF came at their numbers; that is, how they distinguish between fighters and civilians when buildings have collapsed on top of inhabitants, and on-the-ground, independent reporting is impossible," she said.
The RAF insists it has taken extreme care to avoid civilian casualties and that this has been the most "precise" air campaign in history.
An MoD spokeswoman said: "After every British airstrike we conduct detailed battle damage assessment, which thoroughly examines the outcome of the strike against its target, be it Daesh fighters, weapons, or bases.
"This assessment also looks very carefully at whether or not there has been any civilian casualty or damage to civilian infrastructure."
Airwars said a possible reason behind the UK’s refusal to acknowledge civilian harm was due to a reliance on “observable” evidence as proof while dismissing reliable reports from the ground.
The UK-based war monitor said the coalition almost never conducts field investigations, instead relying heavily upon remote analysis.
“This inability of the coalition to properly model ‘unobservable’ civilian harm in urban fighting – even though this is likely how most non combatant deaths and injuries occur – is in the view of Airwars likely to be a key reason why the coalition continues significantly to undercount civilian harm,” Chris Wood, Airwars director, said.