WESTMINSTER magistrates’ court has revoked an arrest warrant for a Sri Lankan army officer just days after it was issued, in what may become a major diplomatic row.

On Monday, the court convicted Brigadier Priyanka Fernando in absentia of public order offences he committed while stationed in London as a military attache at the Sri Lankan embassy.

The soldier was caught on camera repeatedly making slit-throat gestures at Tamil protesters outside the high commission last year, causing them “harassment, alarm and distress.”

He quickly left the country and the Metropolitan Police failed to press charges, forcing Tamils to pursue a private prosecution.

The court heard that he had been involved in the last stages of the Sri Lankan government’s war against the Tamil separatist movement in 2009, including the bombing of a hospital.

His conviction sparked outrage among Sri Lankan nationalists, who regard Mr Fernando as a war hero.

Sri Lankan state-owned media reported that the president’s counsel and foreign ministry were criticising the conviction.

They claim variously that Mr Fernando had diplomatic immunity and was not served with any summons.

However the private prosecutors told the court on Monday that they had served the summons to him through five different channels.

Chief Magistrate Sonia Henley said she was “satisfied every effort had been made” to serve the charges on him and decided to proceed with the trial in his absence.

However the court now appears to have come under pressure to review the conviction.

The private prosecution team has been called back to court and will have to discuss immunity issues next Friday, February 1.

Britain’s Foreign and Commonwealth Office (FCO) has denied any interference in the judicial process, saying that: “The FCO, which is not a party to these legal proceedings, has been contacted by Westminster magistrate’s court seeking clarification of the Brigadier’s diplomatic status in Britain at the time of the incident.

“The FCO is providing documentation to assist the court. Britain is committed to upholding the rule of law, including the Vienna Convention on Diplomatic Relations.”

Britain remains a close ally of Sri Lanka. Their new envoy visited the FCO’s Asia minister Mark Field MP just days before the Brigadier’s trial, to strengthen “the strong bilateral relationship.”