Gardai with suitcases in which they were believed to be carrying machine guns protected a government minister on a visit to Dublin in 1985.
NIO minister Nicholas Scott had been in Dublin to attend the Aer Lingus Young Scientists Exhibition.
A confidential note about the visit said that it had been productive and “the minister was very pleased he had decided to attend it”.
The note by the Conservative minister’s private secretary, AJ Whysall, added: “Mr [John] Lyon may like to note that the security arrangements for the visit seemed to me to be thorough.
“The minister was followed throughout his time in Dublin by two plain-clothed members of the Garda, carrying rather obtrusive briefcases, which I believe to have contained machine guns.
“They tailed him on his drives (for which he had the use of an armoured Embassy car, of course), in an unmarked vehicle.”