This article was originally published in The Guardian and written by Airwars’ head of investigations Joe Dyke and Emma Graham-Harrison of The Guardian. The original version can be read here.

It sounded like accountability. Pressed about the UK’s implausibly spotless record in its bombing campaign against Islamic State in Syria and Iraq, the British government admitted in May 2018 that its military had killed one civilian in eastern Syria two months earlier.

But the strike the then defence secretary, Gavin Williamson, described to parliament was not logged in the records of civilian casualties kept by its allies in the international coalition flying bombers and drones over Syria and Iraq.

Nor does it appear in a list of UK attacks that killed militants, even though the target was three fighters, an investigation by the Guardian and Airwars, a nonprofit research organisation, has found.

And Syrian human rights groups and journalists, who have collected far more extensive databases of civilian deaths and injuries than foreign militaries, have no record of a civilian death in the area on that day.

So Britain’s only recognised civilian casualty of an eight-year aerial bombing campaign against IS apparently came in a strike that did not officially harm anyone, on a victim who does not appear to officially exist.

The UK government has for years said it fought a “perfect” war against IS in Iraq, killing more than 3,000 militants without harming a single civilian. In Syria, the official record is marred only by the single victim reported to parliament.

This government position has been questioned by top retired military officers and defence officials. The former head of GCHQ and permanent secretary of the Ministry of Defence, David Omand, said it “invites challenge”.

A Guardian investigation has identified six strikes in the Iraqi city of Mosul that killed civilians and appear to have been carried out by British forces.

The discovery of serious contradictions in the government account of the only civilian death accepted by UK authorities adds to concerns about Britain’s ability or willingness to document civilian deaths and injuries caused by its bombing campaign.

The only record of this strike, or of the death the government claims it caused, came on 2 May 2018 in a written statement to the House of Commons.

Britain’s allies had accepted killing hundreds of civilians in the bombing campaign, now nearly four years old, and pressure was growing over Britain’s claim that its war had not harmed a single Iraqi or Syrian civilian.

The previous day, a BBC investigation quoted an anonymous senior member of the coalition, who claimed the UK was ignoring allegations of civilian harm from its airstrikes.

The statement provided several important details. It described a hellfire missile strike aimed at three militants. “A civilian motorbike crossed into the strike area at the last moment and it is assessed that one civilian was unintentionally killed.”

It said the strike was in eastern Syria, a vast area roughly half the size of England that was relatively quiet at the time.

It made clear the strike was carried out as part of the US-led coalition, and said the attack had been referred to the specialist unit for investigation. “As with any serious incident, the wider coalition also conducts its own investigation and will report in due course,” the statement said.

The coalition assessed only one report of a civilian casualty incident in eastern Syria on that day, giving the location as Abu Kamal, an area on the Iraq-Syria border, the last IS holdout at the time.

In summary of their findings, released several months after Williamson’s statement to parliament, investigators ruled out any civilian deaths in a coalition strike in the area.

“After a review of available information it was assessed that no coalition strikes were conducted in the geographical area that correspond to the report of civilian casualties,” investigators for the alliance concluded.

This conclusion was reached, even though coalition standards of proof were more relaxed than British ones.

It operated on a “balance of probabilities” basis to accept deaths and injuries. The UK had not explained how it determined civilian harm but was believed to have a threshold similar to the “beyond reasonable doubt” used in British courts.

There are three acknowledged British strikes across Syria and Iraq that the coalition accepted caused civilian casualties. The UK continues to insist no civilians were harmed in those attacks.

The strike described to parliament in 2018 is the only known case where the UK says a civilian was harmed, and the coalition found the opposite.

Absence of records

The strike is also inexplicably absent from recently released UK records. The British government last year provided Airwars with logs of location and date for all RAF airstrikes that killed militants, in response to a freedom of information request.

The strike on 26 March described in the statement to parliament should have been included, because it hit three fighters as well as the civilian. But the data shows no British strike that killed militants anywhere in Syria on the day in question.

British authorities have always publicly said the RAF conducted strikes only as part of a coalition in Iraq and Syria.

If a British strike killed a civilian on the date and place, and in the way described by Williamson, these records raise questions about whether it was part of the coalition mission – or if the UK was acting alone, about the target, the justification and the legality of the attack.

If details of the strike raise serious questions, so too does the identity of the civilian allegedly killed.

Syria has relatively high levels of internet connectivity and many non-government organisations that systematically recorded the names of those killed in its long civil war, either to ensure a permanent record or in the hope of justice in the future.

Their multiple databases include many more civilian victims than parties to the conflict, including thewestern alliance, accept killing. Yet none of them have any record of a civilian being killed on that day, in eastern Syria, in circumstances that match those described by Williamson.

Six separate Syrian nongovernmental organisations that collate data on civilians killed in the war told the Guardian they had no recorded deaths for that area on 26 March 2018. They included Deir Ezzor 24, which specialises in the region where the incident took place.

Local Facebook groups for towns around Asshafa, often busy with news of casualties, had no record of any civilians killed in that area on that date.

The absence of any record of a death in Syrian records is not in itself absolute proof that no civilian was killed. Despite the best efforts of Syrian and international researchers, some civilian deaths were never recorded.

However, the conflict in this part of Syria was tapering off in early 2018. Airwars recorded six civilian harm allegations in that region that month, compared with hundreds during intense periods of fighting in cities such as Mosul and Raqqa.

That greatly lessened the likelihood of this strike going unnoticed or undocumented by local communities, who had more time and energy, and took fewer risks, collecting evidence on civilian deaths that did happen.

At the very least, the absence of this civilian from any databases is evidence that the UK government did not reach out to Syrians to investigate the death.

The Ministry of Defence declined to comment directly on discrepancies in the UK public record, with coalition public statements or with data from Syrian groups.

“A highly trained and professional team of UK military personnel assessed a civilian fatality had been caused,” a spokesperson said.

“We remain confident in the transparency of our reporting and data published by the department can be considered as authoritative on UK military operations as possible.” Williamson did not respond to requests for comment on his statement.

UK claims ‘invite challenge’

To date, this strike remains the sole occasion the UK has officially accepted harming civilians in nine years of bombing IS in Iraq and Syria.

In that time British aircraft have launched more than 4,300 munitions, and the Ministry of Defence claims to have killed more than 4,000 IS militants – in effect claiming a “perfect” war in Iraq that did not harm a single civilian, and a near-perfect one in Syria, with just one death.

The coalition overall has accepted its strikes killed at least 1,437 civilians, the majority of them in American strikes.

Omand said the UK government’s position on civilian casualties “invites challenge”.

In a question to an Oxford Media Network event, with the former chief of defence staff Gen Sir Nick Carter, Omand said he did not personally have any details about civilian casualties in the fight against IS but suggested the official claim of a ‘perfect war’ in Iraq lacked credibility.

“Why aren’t we much more on the front foot saying our operations are necessary, they are proportionate but they don’t always achieve the results?” he asked Carter, criticising “the defensive crouch, whenever there’s a suspicion that something hasn’t quite worked out”.

Government openness about civilian casualties should bolster confidence in the military’s ability to protect civilians, and ministers’ willingness to be transparent about how Britain wields lethal powers.

Yet questions about the nature, location and impact of the 26 March strike are so fundamental that the government statement only undermines trust and raises more questions than it answers.

Carter, responding to Omand, backed a strategic argument for greater openness. “I very much agree with you (Omand),” he said. “I’ve always believed one is far better off being honest and transparent. Our institutions are the backbone of our democracy. And those institutions need to be able to speak honestly about what is happening. It mustn’t be politicised.”

Yet the Ministry of Defence is fighting a lengthy and expensive legal campaign to avoid releasing further details of the strike, including the location, after a freedom of information request by Airwars.

The MoD has said publishing details could jeopardise national security, relations with friendly countries and put individual staff at risk, even though other members of the coalition are far more transparent.

The Netherlands has paid millions in compensation to victims of its strikes. This week, after journalists found new evidence of civilian casualties from a Dutch attack in Mosul in 2016, it announced a fresh inquiry into the strike, and recently released large amounts of classified information about other strikes on IS targets.

The US has launched significant policy reforms to learn lessons for future wars. American authorities also released 1,300 documents to the New York Times after a freedom of information request. Many offer granular details of strikes including chat logs between drone pilots.

The UK information commissioner acknowledged Airwars’ complaint that the MoD’s approach appears “less transparent” than its US counterpart.

A tribunal hearing this year will decide on the freedom of information request, in effect determining how much the British public has a right to know about civilians killed in their name in the fight against IS.