The Solicitors Regulation Authority (SRA) has said it will challenge the decision to clear Leigh Day of allegations it pursued false claims of torture and murder of Iraqi civilians by British troops.

The body confirmed that it was planning to appeal the Solicitors Disciplinary Tribunal’s (SDT) decision to clear the human rights firm and three of its solicitors in June, saying the misconduct allegations were found “not proved”.

A spokesperson for SRA confirmed the decision to appeal but could not comment further because the proceedings are still live.

The firm’s co-founder Martyn Day was one of three lawyers who were accused by the Solicitors Regulation Authority (SRA) of “endorsing” allegations that “the British Army had unlawfully killed, tortured and mistreated Iraqi civilians”.

The other two lawyers involved in the seven-week trial were Sapna Malik and Anna Jennifer Crowther, who faced 19 charges before the SDT.

Leigh Day was first instructed in 2007 by a number of Iraqi citizens who sought compensation from the Ministry of Defence.

They alleged they were unlawfully detained, injured or killed by British forces in Iraq in a 2004 incident known as the “battle of Danny Boy”.

The Al-Sweady inquiry was launched in 2009 to analyse the claims, concluding five years later that the “allegations of torture and murder are untrue and that all of the 28 dead were killed in fighting with British forces”.

Leigh Day and Public Interest Lawyers were the subject of criticism by defence secretary Michael Fallon in 2014 following the publication of a report into allegations that British forces tortured and executed Iraqi citizens.

The charges against the Leigh Day lawyers were brought by the SRA at the end of 2015 and published last summer.

A spokesperson from Leigh Day said: “We remain confident in the decision reached by the SDT in June this year, but naturally we uphold  the rule of law, and therefore, if the SRA chooses to appeal the verdict of the SDT that is entirely a decision for them.”

A hearing on costs started on Monday. No decision has yet been made. The Law Society Gazette reported that Leigh Day has applied for the SRA to pay 60 per cent of its final costs, but the SRA has contested this.