Besides evoking a reminder of how great British music is and bringing back memories of a wonderful couple of weeks, it was also an important landmark for another big reason: it was the day that, under the Olympic Charter at the time, the eight-year statute of limitations expires.

It means that any athlete whose doping sample from London 2012 has not been re-analysed – or whose case is not already in the system – can now not be prosecuted or have their medal taken away or their result annulled. The International Testing Agency, who have been carrying out the re-analysis of the London 2012 samples on behalf of the International Olympic Committee (IOC), confirmed in June that they had now completed their work. It is thought up to a dozen cases remain outstanding.

According to Bill Mallon, the editor of Olympedia, a total of 139 athletes have so far been disqualified from London 2012 because of doping, 65 of them caught in the re-analysis programme. Others have had their performances struck from the record books because of information obtained from officials studying their athlete biological passport or because of evidence obtained during the investigation by Canadian lawyer Richard McLaren into allegations of state-sponsored doping in Russia.

The figures are eye-watering and include 39 medallists, 13 of them who won gold, inevitably leading to headlines like this in The Guardian, "London 2012's 'clean' Games boast in ruins as failed doping tests pile up" or, in The Evening Standard,"Was London 2012 Olympics the dirtiest Games ever?"

Statistically, this is not even a contest. If this was a long-distance race, then London 2012 would have lapped every other Olympic Games in history.

The only Olympic Games that has a comparable rate for positive cases is the predecessor to London, Beijing 2008, where there were 81 athletes disqualified - 65 of them during the IOC's re-analysis programme. Even more medallists were caught at these Games in the Chinese capital than at London 2012. A total of 51 medals were taken away, including nine gold.

Russia led the table of shame at London 2012 with 46 of their athletes being disqualified. They were followed by Ukraine with 17, Belarus with 15, Turkey with 14 and Kazakhstan with six. Overall, a total of 28 countries had athletes disqualified because of doping offences.   

Athletics was the sport which produced the largest number of disqualified athletes for doping with a total of 91 having their performances annulled. Weightlifting followed with 34 and cycling and wrestling had four each. Boxing, canoeing, gymnastics, judo, rowing and swimming all had one each.

But just because London 2012 has seen more athletes disqualified than any other Olympics, does that really make it "the dirtiest Games in history?" Does that mean Moscow 1980 was "the cleanest Olympics in history" because it is the only Games since drugs testing was introduced at Mexico City 1968 not to have had a positive? That would be absurd.

Was London, in fact, the "cleanest" Olympics in history due to the scale of testing that was carried out even after the competitors had packed up and headed home? Never have athletes had to face a situation where the urine or blood sample they gave after their competition in 2012 would be subjected to rigorous new state-of-the-art testing methods for so long afterwards. Only now can those athletes who know they cheated but have not been caught begin to rest easily. 

Since the re-analysis programme was introduced by the IOC at Athens 2004, a total of 148 athletes have been caught in the Summer and Winter Olympics.

As chairman of London 2012 and now President of World Athletics, overseeing the sport which provided the largest number of positive tests, you would expect Sebastian Coe to be horrified at the amount of athletes cheating at the Games he devoted nearly 10 years of his life in successfully bidding for and then organising. In fact, he is delighted.

Parallels can be drawn between anti-doping and the current COVID-19 pandemic crisis. As countries have carried out more testing to try to detect and isolate the virus, numbers testing positive have risen.

"If you don't go fishing, you don't catch fish, and the level of technology applied to testing in London was a completely different order than at previous Games," Coe said.

"I would rather have the ability and technology to retrospectively test and, on some occasions, come up with some embarrassing positives.

"It would have been nice to have been able to do it at the time, but we were able to weed out people that did traduce their performances or traduce the performances of other athletes."

Going back to Moscow 1980, if such a re-analysis programme had existed as was adopted for London 2012, then the number of positive tests might have run into the hundreds. 

In 1989, a report by a committee of the Australian Senate claimed that "there is hardly a medal winner at the Moscow Games, certainly not a gold medal winner...who is not on one sort of drug or another: usually several kinds. The Moscow Games might well have been called the 'Chemists' Games.'"

Indeed, after those Olympics had finished, Manfred Donike, a member of the IOC Medical Commission, privately ran a series of drugs tests using a new technique for identifying abnormal levels of testosterone by measuring its ratio to epitestosterone in urine. A total of 20 per cent of the specimens he tested, including 16 gold medallists, would have resulted in them being banned if it had been applied officially.

Similarly, four years earlier at Montreal 1976, when East Germany made its breakthrough at the Olympics by winning 40 golds. The women's swim team alone won 11 of the 13 events in the pool, an unprecedented feat. Years later Stasi files uncovered evidence of a state-run doping programme.

It was not just athletes from Eastern Bloc countries who engaged in pharmaceutical programmes. There is plenty of evidence to show that United States athletes, either helped at university or funded by their shoe companies, were using banned drugs to try to get ahead.

A few years ago, a study of West German sports, from shortly after World War Two through the Cold War, focused on the doping activities of the Federal Institute of Sports Science, created in 1970 under the jurisdiction of West Germany's Interior Ministry.

The sports institute financed studies of steroids, testosterone, estrogen, growth hormones, insulin and blood boosters like erythropoietin to establish "systemic doping under the guise of basic research", concluded the study by researchers at Humboldt University in Berlin and the University of Münster.

In Britain too, doctors have come forward to admit they helped some of the country's biggest names use anabolic steroids to help power them to Olympic glory.

Being able to test athletes' samples for up to 10 years after the Olympics - the period was extended in 2015 - is a valuable new weapon in the armoury of the drug-testing authorities, claims the World Anti-Doping Agency (WADA) President Witold Bańka.  Only time will tell, though, if it leads to a shift in the mentality of top athletes whose focus is usually relatively short-term rather than what may happen in the future, often several years after they have retired and memories of their moment of glory have long faded. 

"The 10-year statute of limitation that exists under the World Anti-Doping Code reflects WADA’s belief that retesting as science advances is a powerful means to protect clean sport," Bańka told insidethegames.

"Under the Code, athletes who have broken the rules cannot rest easy until a full decade later. As such, retrospective analysis is an important tool for catching cheats and a strong deterrent for those considering it.

"Re-analysis conducted on samples taken at the 2012 Olympic and Paralympic Games in London, has proven to be effective. It means that justice can be served - even if it is years later - thanks to new or improved detection methods. 

"Athletes who unfairly missed out on medals can then enjoy their belated moment of glory and recognition. It sends a clear message that we will not stop seeking justice for those who have been cheated and that we will always stand beside the athletes who choose to compete clean."

The thought process of many athletes at the world-class level was encapsulated by Lance Armstrong (aka "the biggest drugs cheat in history") during an interview last year in which he again tried to justify why he doped.

"I knew there were going to be knives at this fight," the cyclist, stripped of all seven of his Tour de France titles when the scale of his doping was uncovered, told the American network NBCSN. 

"Not just fists. I knew there would be knives. I had knives, and then one day, people start showing up with guns. That's when you say, do I either fly back to Plano, Texas, and not know what you're going to do? Or do you walk to the gun store? I walked to the gun store. I didn't want to go home."

More than a year before London 2012, Britain's then Sports Minister Hugh Robertson had warned that "doping is the most serious threat in sporting terms for the London Organising Committee".

Nearly a decade on, Sir Hugh - now chairman of the British Olympic Association - does not believe that it is the massive number of doping cases which scarred London 2012, but the fact it just highlighted how few athletes had been caught before.

"The tragedy of recent Olympic Games is that we will never know how many clean athletes have been denied medals by doping cheats," he told insidethegames. "The fact that more doping violations have been detected at London 2012 than in any other Games simply proves the scale of the problem. It is scant consolation that so many have been caught."