In 1983 Joe Joyce and Peter Murtagh published The Boss: Charles J. Haughey in Government. The book, a runaway best-seller and a landmark in Irish investigative journalism, was full of revelations about the extraordinary conduct of the affairs of state in the period that became known as the GUBU era.

It also contained, in its draft form, a general description of the Haughey persona, which included the following sentences: "His interest in the sexual exploits of others was matched by gossip about his own sexual activities. In political circles, and at some levels of Dublin society, his lengthy liaison with the wife of a judge was widely discussed."

Amid all the sensational and sometimes terrifying revelations in the manuscript of the book, it was this last sentence that caused most grief to the libel lawyers acting for the book's distributors. The tapping of phones, interference with the courts and the Garda, one member of the Government secretly taping a conversation with another: these things could be written about.

But to hint at the relationship between Charles Haughey and Terry Keane was to take too big a risk. The lawyers would not agree to the inclusion of the sentence unless it could be shown that people who knew about the affair would agree to give evidence in a possible libel trial. No one - including journalists who had witnessed certain relevant incidents - would agree to do so.

In The Boss as it was published, the relevant sentence on page 102 reads: "In political circles and at some levels of Dublin society, his lengthy liaison with a married woman was widely discussed." The fact that Charles Haughey was not faithful to his marriage vows had been revealed. The information that the once and future Taoiseach had as his long-term lover the wife of a judge remained within political circles and at certain levels of Dublin society.

For the next 16 years the affair retained a kind of twilight existence. It was mentioned in Private Eye and Phoenix. It provoked an editorial on hypocrisy in the Sunday Tribune threatening to reveal the name of a senior politician engaged in conduct at variance with his public stand on morality and the law (a threat that was never, of course, made good). It was alluded to on Scrap Saturday.

It was assumed by journalists and politicians to be one of the basic facts about Charles Haughey. Just as "everyone" knew that Haughey was on the take, "everyone" knew that Haughey was an adulterer. But everyone did not include the bulk of the population, and the knowledge, because it was vague and abstract, remained inert.

Until, that is, it became a weapon in a commercial dispute. The revelation of Haughey's financial affairs and of his sexual hypocrisy moved along parallel tracks. Just as his financial venality emerged into the open as a side-effect of the struggle for control of Dunnes Stores, so the revelation of his affair with Terry Keane was collateral damage in the war between Rupert Murdoch and Tony O'Reilly for long-term control of the Irish Sunday newspaper market.

The public owed its final enlightenment, not to the investigative journalism of The Boss in which the affair was set in its proper context, but to the overspill from a media power struggle.

For Terry Keane, as a journalist, her relationship with Haughey was a saleable asset. Its aura gave her social column in the Sunday Independent an interest it would not otherwise have, and it was at least part of the reason she was hired at a salary considerably higher than the one she had enjoyed at the Sunday Press. In the strange and extremely profitable package that the Sunday Independent became from the mid-1980s onwards, the secret life of Charles J. Haughey had a real allure.

For the Sunday Independent, its columnist's relationship with Haughey had to be handled delicately. To profit from it, it had to be the subject of a stream of references. It had to be visible enough to be exploited. But it could not be too visible, for if it were entirely revealed, it would lose its value. There might be a few weeks of sensational serialisation, but afterwards the Keane Edge would be utterly blunted.

SO the strategy was one of media striptease. The basic assumption that a newspaper's job is to tell its readers things they don't know was replaced with the bizarre process of a newspaper teasing its readers with the knowledge that it knew something that they didn't.

Readers were granted glimpses of naked flesh, of "Venice in February" with Charlie, of "early spring on the island with the dear", of how "the secret of a stable government is a stable mistress", of "Charlie, my petit matelot". And then, without so much as an "Oooer, missus", the veil would be drawn again.

It was a very peculiar exercise, halfway between full-blooded British tabloid sensationalism and Irish cute-hoor reticence. But in fact, it quite suited a newspaper whose centre of gravity lay precisely in that ambiguous terrain. It was perfectly adapted to the Sunday independent's broader attempt to invent a glamorous, exciting Irish upper crust that did not really exist. The mundane and painful reality - that the Taoiseach was a hypocrite - was proposed as a frightfully sophisticated parlour game.

This might have gone on indefinitely were it not for the growing presence of a very different kind of media culture. Rupert Murdoch has not built his global media empire on half-measures. The word "reticence" is not in his vocabulary. His newspapers in Britain made a great deal of money by finally jettisoning the old approach of hints, inklings and overtones that had made the royal family seem glamorous without actually exposing their sexual peccadilloes.

Coming from a media culture in which every sweaty little passion of Charles, Diana, Camilla, Fergie, Andrew and a constantly changing cast of Sloanes and guardsmen had been paraded to the great delight of Murdoch's bankers, the coy little game that the Sunday Independent was playing with the tale of Terry and her petit matelot must have seemed pretty silly stuff.

The ethic of Murdoch's newspapers is not just sensationalist, though. It is also ruthlessly competitive. It thrives on the "double whammy" in which a story, at one and the same time, boosts your own circulation and kicks the opposition where it hurts. In Murdoch's centre of operations at Wapping in London, there were three slogans on the wall: "News is anything that makes the reader say Gee Whiz"; "If you do it, do it big"; and "Do it to them before they do it to us."

The winning of the Terry Keane story for the Sunday Times is a classic Murdoch exclusive because it lives up to each of these three commands. The Sunday Independent's coquettish treatment of the story, it makes the reader say "Gee Whiz!", or, this being Ireland, "Holy Jaysus!" Instead of using a verbal semaphore that needs to be decoded, it does it big.

And, perhaps most importantly of all from a strategic point of view, it does it to the Sunday Independent before the Sunday In- dependent can do it to the Sunday Times. In this case, Murdoch walks away with the prize and the gal, with Keane's revelations and with her column.

It is hardly surprising that in the immediate aftermath of this shock, the Sunday In- dependent managed to make itself look silly by attempting to adopt a high moral tone.

Running "A lover's final betrayal of Charles J. Haughey" as a front-page headline is not a great idea when you have been titillating your readers with the same relationship for years. Flooding the airwaves with tales of how your star columnist didn't write much of what appeared under her name seems like a rather spectacular case of cutting off your own credibility to spite hers.

If, as Sunday Independent editor Aengus Fanning told his readers, Terry Keane made "no contribution" to the paper, who did write all that stuff and why did he or she choose to remain anonymous?

And yet the irony is that the Sunday Times's victory over its rival may prove Pyrrhic. The short-term boost in circulation for the Sunday Times seems substantial, but similar rises for other Irish Sundays on the back of sensational stories have often proved to have little long-term effect. Terry Keane's future value to the paper as a gossip columnist may be somewhat diminished by the loss of her ability to drop thrilling little hints.

Without having to consider her feelings, moreover, the Sunday Independent may be in a much better position to use the material which its journalist Kevin O'Connor has unearthed for his book, Sweetie, due to be released in a fortnight. And, by putting an end to the Keane Edge, the Sunday Times may have done its rival an enormous favour.

It should not have taken Rupert Murdoch to free the Sunday Independent from a style of gossip that probably alienates more readers than it attracts. But, maybe for the first time in his career, Murdoch has given a newspaper the chance to raise its standards of decency and sensitivity.