State papers show the former Kerry South TD came to the attention of gardaí who were investigating alleged fraud by people living in the Rathmore and Barraduff areas of Kerry.
A complaint was made to gardaí by an official from the Department of Agriculture in Tralee that attempts were being made to make false claims under its cattle and sheep headage scheme.
The Department of Agriculture expressed concern that that P60 forms to claim grants were forgeries.
A secret Garda report from 1986 shows a chief superintendent noted that Mr Moynihan, who was then a minister for state at the Department of Trade, Commerce and Tourism, was under suspicion for issuing bogus forms to constituents to enable them to claim headage payments to which they weren’t entitled.
Documents recording interviews with individuals suspected of submitting bogus forms show three out of nine men linked the bogus forms to Mr Moynihan.
One man told gardaí that he had given a genuine P60 form to a TD in Killarney and had got “altered ones” back in the post.
The man said he had voted for the politician because he had been promised he would arrange headage grants.
The witness said he would not reveal the identity of the TD without seeing his “attorney”. Another man said he had got bogus P60 forms in an office where “the whole place were getting them”.
A third man from Killarney told gardaí he got a P60 form from a friend whom he refused to name.
Another suspect when asked if he had got the bogus form from a politician replied: “I suppose it was.” One man questioned by gardaí admitted he had got the forms from the Labour TD. “He got a lot of votes out of the factory [location deleted] over them,” the man said.
Gardaí concluded that bogus forms submitted after 1982 were coming from Mr Moynihan but earlier ones were linked to an office, whose location was redacted.
A Garda report said from evidence it was clear that “a very ingenious fraud” was being committed using bogus P60 forms.
Gardaí said there was widespread abuse of the system in the locality and most of the forms appeared to have a common origin.
The Department of Agriculture said it believed its complaint only represented “the tip of the iceberg.”
Gardaí said further checks should be carried out as P60s were also used to claim health benefits and EEC grants.
“This is a serious fraud and should be thoroughly investigated without further delay,” a garda superintendent recommended.
He warned any press publicity about the case would be undesirable for the investigation to be successful.
Moynihan, who died in 2001, was subsequently prosecuted for his alleged role in the fraud but the case was dismissed in court.
The politician contested every general election since 1954 but was only elected to the Dáil for the first time in 1981 and held his seat until his retirement from politics in 1992 with the exception of one term 1987-1989.
His daughter, Breeda Moynihan-Cronin, held her father’s seat in the 1992 general election.