IDENTIFYING who started the rumour about President Hillery having an adulterous affair in 1979 has become a literary and political whodunit.

A new book by historian John Walsh says it was the late Charles Haughey, and the late President was convinced it was the former Taoiseach who spread the sex smear.

Yesterday Haughey's former press secretary PJ Mara denied that his late boss was involved and said the rumour began in Brussels.

Dr John Hillery, the late President Hillery's son, said that his late father's trusted friends in Europe told him about the slur and Mr Haughey's alleged role in it.

Dr Patrick Hillery, who died aged 84 in April, never spoke publicly about the rumour although he was understood to be very hurt and upset by it.

The first call asking if President Hillery was having an extra-marital affair was made as he was attending a Mass celebrated by the Pope in Phoenix Park.

Earlier Dr Hillery had greeted the Pontiff at Dublin Airport when he arrived for his historic Irish visit and a few hours later the delicate inquiry was made to Aras an Uachtarain.

I was asked to make the call after a colleague confirmed that a reporter from a Belgian French-language newspaper filed a story saying that Dublin was rife with the rumour.

When I called and said I had a very sensitive question to ask, the person who answered replied that the President and his aide de camp were at the Mass and asked me to leave a number.

In 1979, the prospect of revealing that the Irish head of state was involved in an adulterous affair was never going to be reported without being thoroughly verified.

And when the President's aide returned the call and I put the question to him, he said it left him in an appalling predicament: if he said it wasn't true, would we publish his denial?

I TOLD him that if the continental newspapers reported it, the British media would pick up any scandal and it would inevitably be repeated in Ireland.

However, I said, if he assured me as a man of honour that the story was not true, the 'Sunday World', the newspaper I worked for then, would not publish his denial.

The President's aide said there wasn't a word of truth in the rumour and I assured him that the story would not be published -- and it wasn't.

But a few days later Dr Hillery called the editors of the national newspapers and RTE to explain his difficulty and they suggested he brief their political correspondents.

Addressing the political correspondents, the late President Hillery was embarrassed but eventually denied emphatically that he was having an affair.

Sean Duignan, the then- political correspondent for RTE, said he had a deadline and left before Dr Hillery said the briefing was "off the record".

Duignan told the story of the president denying the affair on that evening's 'Nine O'Clock News' and it was repeated in the next morning's national newspapers.

What had been a scurrilous rumour whispered between a small circle of journalists and insiders became a national talking point after it was reported in the national media.

The story grew legs after that. An Italian and a French national who had worked with Dr Hillery in Brussels were even named as 'the other women'.

Reporter John Cooney who worked in Brussels at that time, and who would have picked up any gossip around the nine-member EEC headquarters, said he heard nothing about it until the denial appeared in the Irish media.

Cooney and others in a position to take an informed view, believe the story originated in Dublin rather than Brussels and none of them believed it was true.

Nobody took the rumours seriously and assumed Dr Hillery was a decent man wronged by rumour mongers, but the tittle-tattle caused great upset and hurt to the then President and his family.

Who started the rumour? Nobody knows for sure, but everybody has suspicions.

And finding the origin of a rumour is not as scientific a project as discovering the source of the Nile. But those who passed it on were just as guilty of giving scandal as whoever first uttered the words -- and for a few weeks in September 1979 the chattering classes spoke of little else.

ssmyth@independent.ie

- Sam Smyth