According to journalist Richard Norton-Taylor, "Rosenfeld was approached in 1991 by the Joint Services Group, a cover name used by army intelligence in Northern Ireland." Under the alias Tommy Doheny, he set up a construction company at the army's request, which allowed him to cross the border frequently from his home in in Enniskillen, County Fermanagh, in order to pass on information about republican activities.
He subsequently pleaded guilty to stealing a car before Omagh Magistrates Court, although the company which owned the car later said it regarded the issue as a civil matter of a breach of lease conditions. He was sentenced to 12 months on 12 March 1993, but was allowed to cross the border to the Republic.
In December 1993, he travelled to England to pursue a complaint against the police, but later returned to Ireland. He was asked to come to London for an interview by the Metropolitan Police in May 1994, and was then arrested. Army intelligence blocked his transfer to Northern Ireland, and he served his previously imposed sentence at HMP Pentonville. He was released in November 1994.
- Henry McDonald, Army spy faces jail after appeal to Queen over 'murders', Observer, 7 December 2003.
- Harry McGee, Former spy's claims reveal British espionage in Ireland; Allegations of one-time agent Samuel Rosenfeld show British military spies operated routinely in the Republic, Sunday Tribune, 1 June 2003.
- Richard Norton-Taylor, FORMER ARMY AGENT 'FRAMED' BY RUC FIGHTS FOR JUSTICE; Richard Norton -Taylor on a spy who fell foul of the intelligence rivalry between police and military in Northern Ireland, The Guardian, 28 August 1996.