It took until the sixth morning of finals, the sixth gold medal and the sixth world record before the "D" word was raised. "So, Michael, with all the talk of amazing performances of Marion Jones [plus a list of several other US athletes banned for doping or linked to drugs scandals] ... what would you say to those who say that your performances are too good to be true?"

Phelps, who is aiming to break Mark Spitz's 1972 record of seven golds at a single Games tomorrow in the 100m butterfly and would soar past the legend on Sunday in the medley relay if the USA comes up trumps, shrugged and replied: "They can say what they want. I am clean. I did 'Project Believe' with USADA (U.S Anti Doping Agency) where I purposely wanted to do more tests to prove that. People can question all they want but the facts are facts and I have the results to prove it."

"Project Believe" is a voluntary testing programme that also includes sprinter Allyson Felix and decathlete Brian Clay where the participants provide additional blood and urine samples beyond the regular testing regime. Phelps's image features prominently on USADA's website and he is also featured in the organisation's 'My Victory' campaign, which encourages young athletes to take a pledge against doping.

Phelps, 23, now has an unprecedented 12 career Olympic gold medals, three more than previous record holders Paavo Nurmi (FIN, track and field), Larysa Latynina (URS, gymnastics), Spitz (USA, swimming) and Carl Lewis (USA, track and field). The superstar of the Water Cube and a man who has sparked a debate about what constitutes "the greatest", noted that his training regime is constant, tough and specialised. He had got to where he was on a diet of hard work.

"With a programme like I have, I have to work on speed and endurance and all four strokes. I need the speed to take it out (at the start) and the endurance to carry it through," he said. "You can't do it on talent alone. A lot of hard work, a lot of dedication.

No questions yet about the Chinese 200m butterfly girls. The bodysuit issue has masked a fair few things at these Games but the deeper analysis of Chinese results over the weeks to come cannot be avoided. And is critical as we head into a year where we will all head back to Rome. Remember 1994 and all of that? Let us pray that history does not repeat itself.

Mention of Phelps and the D word is rare in swimming circles, and for good reason. Like Thorpe and a whole string of other supertalents, his progression is on the chart of the capabilities he has shown for many years throughout a journey in the sport from his youth.

It goes without saying, of course, that drugs are part of sport and that cannot be denied. Take this little lot. 

Timeline of major doping incidents issued by Reuters today:

• April 4: Eleven of the 14-member Greek weightlifting team fail dope tests. They are later banned for two years and excluded from Beijing.
  
• June 27: China's top backstroke swimmer, 25-year-old Ouyang Kunpeng gets life ban after positive test for banned steroid clenbuterol. Coach Feng Shangbao also banned for life.
• On the same day, Bulgaria withdraws its national weightlifting team from Beijing, after 11 members test positive for banned anabolic substance methaienon.
• July 2: Wrestler Luo Meng becomes second Chinese Olympic hopeful to be banned for life after testing positive for banned diuretic. Coach Zhang Hua also banned for life.
• July 10: Liliana Popescu, the fastest women's 1,500 metres runner this year, dropped from Romanian Olympic team under suspicion of doping.
• July 28: Italian cyclist, world road race champ Marta Bastianelli dropped from Beijing for failing test.
• Aug 2: U.S. swimmer Jessica Hardy withdrawn from Beijing after failing dope test at Olympics trials in July. The 21-year-old medal contender had qualified for two events, 100 metres breaststroke and 50 metres freestyle.
• Aug 4: Italian Andrea Baldini, the world number one foil fencer, fails B-sample dope test a month after an initial positive test and is excluded from Beijing team.
• Aug 5: Russian race walker Vladimir Kanaikin, a favourite for gold in the 20 km in Beijing, suspended after failing test. Two other leading Russian walkers, not selected for Beijing, also suspended after positive tests.
• Italian rider Emanuele Sella suspended by Italian Olympic Committee after failing test. The 27-year-old confesses to taking banned substance three days later.
• Jamaican sprinter, 4x100m relay team member Julien Dunkley, banned from Beijing for positive dope test.
• Aug 6: India woman weightlifter Monica Devi, the lone Indian lifter set to participate at Beijing, withdrawn after she fails dope test at home a week earlier.
• Aug 8: Greek sprinter Tassis Gousis fails a Greek doping agency test. The 19-year-old who was to compete in 200 metres at the Games returns home from Japan training camp.
• Aug 10: IOC bars Greek sprinter Katerina Thanou from Beijing over an Athens 2004 doping scandal which saw her withdraw in disgrace after she and a fellow sprinter missed a drug test.
• Aug 11: Spanish cyclist Maria Isabel Moreno becomes Beijing's first competitor to fail drug test, just hours after arriving. The 27-year old is sent home.
• Aug 13: Taiwan baseball player Chang Tai-shan tests positive for a banned substance in a pre-Games check. He will be barred from Beijing if he fails second test.
• Aug 15: North Korean shooting medallist Kim Jong-su stripped of his silver and bronze medals and excluded from Beijing after positive test. A Vietnamese artistic gymnast, who finished out of the medals, also tests positive for a banned substance.