Sinn Féin is examining allegations made by a man claiming to be a former British undercover soldier that covert cameras are still being used in parts of south Armagh, west Belfast and the Border areas of Co Louth.
Newry Armagh MP Conor Murphy said the allegations posed serious questions for the British government.
The former soldier, who has not been named, made a series of claims to Relatives for Justice, a group representing those bereaved by alleged collusion between loyalists paramilitaries and British forces, in the presence of a reporter from the Andersonstown News, based in west Belfast.
The newspaper carried a report yesterday repeating his claims. The include the allegation that, while based at a British army fortress in Bessbrook, Co Armagh, covert cameras were placed at a range of locations in the county, as well as in Dundalk, a short distance across the Border.
"We were involved in planting hidden cameras in different locations to spy on targets," the former soldier told the newspaper.
"The work was often on behalf of Special Branch." He said the surveillance work was carried out by a unit known as the Covert Observation Platoon (COP).
His claims include the allegation that various cameras were placed in Dundalk and that soldiers working for the British army's COP would often travel into the Republic in connection with surveillance work.
Sinn Féin's Conor Murphy said: "These allegations made by a former British army soldier are very serious.
"It is totally unacceptable for any covert spying on people living in these areas. Only this week the EU Court of Human Rights vindicated local families who were victims of collusion and had family members murdered because of RUC and UDR activities in south Armagh."
He said he will be raising these issues at the highest level politically. "We all know how damaging the activities of the securocrats have been to the peace process and it is up to the British government to bring this illegal activity to an end."
A British army spokesman said: "We don't normally discuss security as normal protocol - anything to do with the Republic is for the Irish Government. We are not involved directly in any investigation which is rightly a matter for the PSNI." There was no comment from Minister for Foreign Affairs Dermot Ahern, who is also TD for Louth.