THERE was a new mystery of the marathon here this week. Questions were being asked of Paula Radcliffe, the heroine of British athletics, whose integrity has hitherto been beyond question.

But then, how can you question someone so polite, so charming and intelligent, fluent in three languages, who speaks well, and who even wears a red ribbon on her racing vest to demonstrate her demand for proper, universal drug testing?

Yet in the build-up to Radcliffe's date with destiny on the ancient road from Marathon to Athens tonight, there were no satisfactory answers from the athlete about a rumoured injury. Nor were there answers to the questions about why she should travel to Munich to visit a physician notorious for his doping links, when her national team has world-class medical back-up and the Irish physiotherapist, Gerard Hartmann, has been her constant companion.

And why, it was asked, had Radcliffe absented herself from the British pre-Olympic acclimatisation camp in Cyprus, preferring to train at a private location in Spain?

How history repeats itself.

Earlier this year, one prominent journalist working for a London newspaper published a book which raised similar questions about Lance Armstrong, just as the American was about to ride off into history with his sixth Tour de France victory.

Armstrong's breathtaking performances, his close associations with an Italian doctor who is being investigated for supplying drugs, plus the testimony of an Irishwoman who had formerly worked as the cyclist's masseuse ? all were "circumstantial evidence", said the author, David Walsh, which justified the asking of legitimate questions. After all, had the right questions been asked sooner, might the Cathal Lombard episode never have happened?

Certainly, few working for British newspapers in the build-up to Steve Redgrave's fourth and fifth Olympic golds ever openly challenged the relationship with the coach Jürgen Grobler, a graduate of Leipzig's College for Physical Culture, the institute that led the world in hormonedoping research. Should Grobler have been placed under extra scrutiny as a result of a dubious East German past?

Of course, the ultimate Athens Olympics fairy story has turned into Greece's nightmare with the farcical antics of Kostas Kenteris and Ekaterina Thanou. The real tragedy of the way the sprinters' failed to attend drug tests has overshadowed the first week of these Games was that their behaviour had been allowed to continue for seven years ? since Thanou's training group attacked a drug tester to dodge the sampling process.

So why should there be such a backlash against those who dare to question Radcliffe? In the media frenzy that has surrounded the Greek sprinters this week, one of the pieces of "circumstantial evidence" held up against them has been their negligible racing programme.

Much the same was common for Michelle Smith, who even relied on racing at a kids' meeting in Florida unannounced to get herself an Olympic qualifying time.

And Radcliffe? After barely racing at all in 2003, the 30year-old from Bedford has made only two track appearances this summer.

What Radcliffe has never done, as Smith did, was to answer questions about the frequency of her drug tests with an outright lie. "I am the most tested swimmer in the world, " Smith brazenly said in Atlanta, when the opposite was in fact the case. Radcliffe, when French journalists for L'Equipe began to question her improvements two years ago, asked UK Sport to post her drug testing record on its website. The world governing body, the IAAF, also confirms that Radcliffe is tested under its scheme. Such bare facts assuage doubts about any lack of testing.

However, UK Sport does have budgetary limits on sending its testers overseas, and on the number of blood tests it conducts. Radcliffe, with training bases in France and Arizona, spends almost half the year outside her home country. We have to wait for Radcliffe to end her self-imposed purdah to explain her visit to German doctor Hans Wilhelm Müller Wohlfahrt. Sian Masterton, her agent, did not deny that Radcliffe had visited Germany. "She went to Munich a month ago for a check-up on her hernia injury, " she said.

Max Jones, the performance director of UK Athletics, said, "She's a regular visitor to Müller Wohlfahrt." So that's alright then.

For there are many questions about the methods used by Dr Müller Wohlfahrt. In the past, Stephen Roche and Linford Christie both visited the Munich surgery of the man who, as official doctor to the West German national football team, had Franz Beckenbauer's squad on anabolic steroids ahead of their winning the 1974 World Cup.

It is understood that Radcliffe is planning to publish an autobiography shortly after the Athens Games, the sales of which would be boosted if she wins the Olympic marathon gold medal today. It is to be hoped that her ghostwriter ? the same author of the book which questioned Lance Armstrong's methods ? will provide a full explanation for all the questions which surround her.