An inquiry into allegations British Special Forces murdered unarmed Afghan civilians has cost UK taxpayers £58m, figures from the Ministry of Defence (MoD) show.

When the inquiry was launched in 2023, its chair Lord Justice Haddon-Cave said it would aim to report, “at least on an interim basis”, within 12-18 months.

However, the inquiry has now been running for more than three and a half years, and has yet to publish any findings.

In a statement, the inquiry said its work was “greater and more complex than it originally envisaged”.

It added that delays by the MoD in disclosing information had also affected the timetable.

The Independent Inquiry relating to Afghanistan (IIRTA) was established to investigate alleged war crimes committed by soldiers serving with the Special Air Service between 2010 and 2013, during so called night raids targeting the Taliban.

These include allegations the SAS murdered detainees and unarmed civilians, including children, during operations.

It was set up by the former defence secretary, Ben Wallace, in the wake of allegations first reported by BBC Panorama, in 2022.

While much of the inquiry’s work has been carried out in closed sessions to protect the identities of serving personnel, it has published some evidence on its website.

It has already heard evidence from senior UK military personnel who have said they believed the SAS carried out extra judicial killings of Afghan civilians.

It has also heard concerns about the secrecy in which the SAS operated and that previous investigations into the allegations were ended prematurely.

The inquiry’s costs were £14.68m, until the end of the 2024-5 financial year. Those included the salary of the chair, Sir Charles Haddon-Cave, its secretariat, lawyers and expert witnesses. The inquiry said its expenditure was proportionate and overseen judicially.

However, the Ministry of Defence has given a much higher figure. Following a Freedom of Information request submitted by the BBC, the MoD put the overall cost at £58m to March 2026.

The figure included the costs to the MoD as well as those of the inquiry team, it said. The MoD said that 74 of its staff were currently working more than 50% of their time on the inquiry.

The SAS Regimental Association (SASRA), which represents more than 5,000 SAS veterans and serving personnel, said it remained committed to supporting the inquiry and helping achieve a “timely solution”.

But in a statement, it added: “The prolonged nature of the process is itself causing significant and widening harm.”

It said the inquiry posed a “significant challenge, not only to the regiment’s reputation and the wellbeing and morale of its members, but in the association’s view, to the operational effectiveness of a key element of the nation’s defence”.

It said the cumulative effect of decades of legal scrutiny arising from operations in Northern Ireland, Iraq, Afghanistan and Syria was placing a significant burden on individuals, families and the association itself.

Public inquiries are rarely quick or cheap. The Bloody Sunday Inquiry, which found the killing of 13 civil rights protesters in Northern Ireland by British soldiers was “unjustified”, took 12 years to complete and cost more than £190m.

In response, the inquiry said it remained committed to the welfare and safety of UK Special Forces personnel, and a timely conclusion to the inquiry was in everyone’s interest.

“The chair remains committed to the welfare and safety of UK Special Forces personnel and witnesses who come forward to the inquiry.”