For an Olympic, world and European champion, Kostas Kenteris is an incredibly impenetrable character.
This is a man who, according to his achievements at the big championships, should be one of the biggest names in world sport.
But while Kenteris was a national hero in Greece, his international reputation was always less clear-cut.
The dramatic developments in Athens in the past week when Kenteris and his training partner Katerina Thanou first missed a drugs test and were then hospitalised after a mysterious road accident, were just the latest in a long line of incidents which left question-marks hanging over his reputation.
Kenteris was a 400m runner going nowhere until he linked up with controversial coach Christos Tzekos in 1999.
Tzekos, who had been disciplined by the IAAF two years previously for allegedly manhandling a doping official trying to test four other Greek athletes, transformed Kenteris into the best 200m runner in the world in a matter of months.
Kenteris went from finishing last in the final of the 2000 European Indoors to Olympic champion within six months, powering his way to gold in Sydney with a stunning display of muscular sprinting.
It was a win which shocked the world. Kenteris, a rank outsider to even reach the final before the Games, went almost a quarter of a second faster than his previous best to take the win.
It should have been the start of a highly-lucrative period for both Kenteris and Thanou, who took 100m silver in Sydney and was also coached by Tzekos.
As Olympic heroes, both were in great demand on the Grand Prix circuit and could have expected to make hundreds of thousands of pounds in appearance and prize money.
Instead, Kenteris chose to go into isolation.
Since his victory in Sydney, the 31-year-old has taken part in just one Golden League or Grand Prix meeting outside Greece, spurning a fortune to concentrate on his training.
Despite - or, to his supporters, because of - this lack of competition, Kenteris came out at the World Championships in 2001 and Europeans the following summer to take two more 200m golds in similarly spectacular fashion.
Seldom interviewed and intensely private, Kenteris remained an unknown character to both his fellow athletes and the world's media.
Greek officials described him as an honorary sergeant in the national air force, a single man who enjoyed the cinema and working with children.
But that was it. There were no news conferences, no public appearances and no international sponsorship deals.
Kenteris' defenders say that he had no need to chase dollars on the European circuit, because the Greek government was funding him to the tune of £55,000 a year.
Tzekos, meanwhile, claims that his coaching success is down to a unique combination of strengthening and stretching work.
But the pair attracted unfavourable rumours when Kenteris and Thanou withdrew from a Grand Prix meet in Athens in 2002 at the very last minute.
Then, last year, the IAAF issued an official warning after Tzekos and his two charges were found to be training in Qatar, rather than in Crete as they had told Greek athletics officials.
Athletes are required to inform their national federations of their exact whereabouts if they leave their usual home address, so that anti-doping officials are able to contact them if they wish to administer out-of-competition tests.
Kenteris had surprised the Greek team by pulling out of last summer's World Championships in Paris just before competition was due to begin, citing a leg injury.
Last week, Kenteris and Thanou missed a drugs test in Chicago when they decided to fly to Greece a day earlier than expected.
That did little to repair the damage done to their images by the earlier incidents - and then came the cataclysmic events in Athens.