The UK government has come under increasing pressure to extend the Pitchford Inquiry into undercover policing into Northern Ireland.

It has emerged Justice Minister Claire Sugden wrote to the Home Office in June to request the extension of the inquiry.

She said it was possible that operations conducted by the undercover units at the centre of the inquiry could have implications for Northern Ireland investigations and inquests.

One of the officers, Mark Kennedy, under scrutiny is known to have attended at least two meetings in Belfast in 2005.

According to Ms Sugden’s letter, the Metropolitan Police have already contacted one Northern Ireland murder victim’s family to “inform them that their officers were present at protest activity relating to the murder” and are planning to contact another.

However, Ms Sugden has not yet received a reply.

The terms of reference, set in July 2015, limits the inquiry to police operations conducted in England and Wales.

The UK government has already refused a Scottish Government request for the inquiry to be extended.

Solicitor Darragh Mackin of Belfast firm KRW Law is acting for a number of Northern Ireland activists and campaigners who believe they may have been spied upon and want the inquiry to be extended.

Mr Mackin told Irish Legal News: “It is common sense that when one state’s forces operates in another without notice, oversight or accountability, then there should be an investigation into that activity.

“It is undoubtedly concerning that the Home Secretary decides, contrary to the Minister of Justice’s request, not to extend the Pitchford inquiry.

“We will now be asking the courts to determine whether that decision, is in fact reasonable or rational. We say it is not.”