Mick Ryan's book gave an account of the 1959 attack

DETECTIVES have questioned a veteran Official IRA member in his Dundalk home about an attack on the B Specials almost 60 years ago.

Mick Ryan was a leading figure in the IRA's border campaign of the 1950s and was at one time the organisation's 'director of operations'.

It is believed that the approach at his home in Co Louth represents the oldest investigation launched in relation to historical republican activity.

It comes as Britain's defence secretary, Penny Mordaunt, has said she wants members of the military who served in Northern Ireland to be covered by proposals to introduce an effective amnesty from prosecutions.

A decision that 'Soldier F', who was present on Bloody Sunday, will stand trial for alleged involvement in two murders in 1972 has strengthened the calls from back-bench MPs.

However, victims groups and lawyers have warned of the potential fallout of an amnesty that would have to legally include all groups involved in the conflict.

Until now this has included investigations into actions carried out by state forces, the Provisional IRA and loyalist paramilitaries from 1969 until 1998.

IRA activities along the border in the late 1950s have not been subject to historical investigation.

Originally from Dublin, Ryan, now aged in his eighties, lives in Dundalk with his wife. He spent a year interned at the Curragh camp in the 1950s and returned to IRA activity upon his release. After the split in 1969, during which the Provisional IRA was formed, he remained with what became known as the Official IRA, holding leadership positions.

On Tuesday two detectives, members of An Garda Síochána, called to Ryan's Dundalk home saying they were making inquiries on behalf of the PSNI.

He spoke briefly to the men who asked questions about matters including the IRA attack at Ballsmill in 1959.

In his book, My Life in the IRA - The Border Campaign, published by Mercier last year, Ryan gives a detailed account of his life in the republican movement.

The book is described as "not an apology" but a "heartfelt description of the hardship, frustration and near-constant disappointment" of what quickly became a "hopeless cause".

Ryan talks in the book about how an arms raid on Gough Barracks in Armagh in 1954 was the event that convinced him to join the IRA, answering an advert to 'join the republican movement' in the monthly newspaper The United Irishman. He joined the IRA in October 1954 and attended his first weapons 'training camp' a short time later.

By 1959 Ryan was appointed to the IRA's seven-member 'army council'.

Mick Ryan's book gave an account of the 1959 attack

In his book he details how Ruairí Ó Brádaigh contacted him and said they needed to organise an attack on security personnel, due to the low morale of members after a number were captured during operations.

He quotes Ó Brádaigh, who died in 2013, as saying: "Try to get someone to throw a grenade or two at a British army patrol in Newry."

The attack on an RUC patrol at Ballsmill in Crossmaglen happened in November 1959. A mine was planted to target a patrol. Three gunmen, including Ryan, opened fire after it was detonated.

Ryan gives a detailed account of the preparation, execution and the aftermath of the attack. Two RUC officers, Constable William Johnston (28) and Special Constable Trevor Boyle (21), who was in the reserve force known as the 'B' Specials, sustained serious injuries.

The book, edited by former Irish Times journalist and author Padraig Yeates, describes the attack in detail with Ryan saying: "The jeep was hit all right, because I could see some parts of it fly into the air and land a few yards away." He then describes fleeing back across the border to the Republic.

When the book was first published last year DUP MLA William Irwin said Ryan should be brought before the courts.

Ryan's solicitor James MacGuill said he would be "making an application to the court" to protect his client who he says is "medically unfit" for questioning.

A Garda spokesperson said: "We do not comment on confirm or deny details of enquiries carried out as part of ongoing investigations."