Michelle de Bruin is hailed as a wonder woman in Ireland but she is swimming against the tide in Britain. Every report of her victories in the European Championships at Seville is not so much laced with scepticism as drenched in a wave of innuendo just a finger-tip short of libel.

After her 400 metres individual medley title, the Express wondered "if her awesome improvements had been fuelled by more than just Guinness and potatoes". If you're going to throw mud, why not lard it with a little old-fashioned anti-Irish racism?

Insinuations about Michelle's performances are not confined to the tabloids. Those supposedly impartial narrators of the facts, the highminded broadsheets, are leading the charge. "Smith celebrates empty triumph," said the Times headline over a piece which, in purporting to report on a campaign of innuendo, substantially added to it.

"Vendettas in the small, occasionally seamy world of Irish swimming are conducted with a subtlety that owes more to expedience than experience," said the Times, which claimed that officials were "privately . . . resentful of having to promote a tainted role model".

But who is doing the tainting? In the London Independ- ent, under the headline "De Bruin's sour success", we are told that "such is the speculation of drug use" that the championships are being suffocated. The writer adds: "De Bruin, who has always denied using drugs and has never failed a drugs test, has been the centre of controversy ever since winning three Olympic gold medals in Atlanta."

The implication could not be clearer. But where is the evidence for these jibes? The In- dependent offers "the reason". It says "her spectacular progress . . . has been beyond the belief of some observers."

Some observers, presumably, being British sports writers and editors. Anyone else? Well, according to several reports, her British opponent in the 200 metres freestyle, Karen Pickering. The Daily Mail said she had "added her voice to the band of sceptics questioning the achievements of Michelle Smith".

Let's look at that more closely. Pickering is widely reported as having said: "With all the suspicions you don't know if you are on a level playing field." This has all the hallmarks of being a reply to a loaded question.

Pickering's somewhat circumspect quote does not justify the Mail's headline "Pickering doubts Smith now". There is more to note in this elevation of a single criticism - by a woman, incidentally, who finished sixth - to the status of a political charge.

The Times's columnist John Bryant referred to "whispers" about Michelle from "some of the American swimmers who suggested that her victories would have been impossible without the aid of performance-enhancing drugs". None was quoted.

Perhaps Bryant was thinking of the report from his paper's swimming correspondent the day before which said there was a "whispering campaign against the Olympic champion [which] shows no sign of losing its momentum. Damning statistics, charting the unlikely nature of her improvements, are routinely leaked."

Leaked by whom? We are not told.

Bryant, also the Times's deputy editor and normally noted for his fairness, goes with this anti-Michelle flow. While accepting that "she trains hard and has never failed a drug test", he adds, "but the questions refuse to go away".

Then he dares to imply that "the procedures for policing drug-taking" leave doubts. "Masking agents are now so good that you can easily disguise drug use if you know a test is coming."

It is inconceivable that British journalists would make such transparent allegations against a British sporting champion. Office lawyers would surely overrule all such allusions for fear of court action for libel.

The other prong of the newspapers' attack is to dredge up the fact that Michelle's husband, Erik de Bruin, has just finished a four-year suspension from athletics after failing a drugs test in 1993. He was then Holland's top discus thrower.

"De Bruin is at the centre of Michelle's mystery," says the Express. Just three years ago she had a modest record as a swimmer, until de Bruin began to coach her "despite a complete ignorance of swimming". Yet the pair, and here comes the nudge-nudge, wink-wink, "have kept their training a closely-guarded secret".

And then, on Thursday, Michelle came second in the 400 metres freestyle. Suddenly all talk of the "controversy" surrounding "Ireland's darling" vanished. Explaining away her victories, using smears without proof, had been easy. It was impossible, given the allegations that had gone before, to account for human fallibility. Too much Guinness, maybe, or an extra helping of potatoes?

Roy Greenslade is the Guardian's media commentator