If you doubt the potency of this tool, just take a look at the six-page “Exhibit” appended to part one of the McLaren report, whose keenly awaited second instalment will be published next Friday (December 9).

Though inadequately labelled, a reference in the main body of the report’s text appears to indicate that this is a report written by Grigory Rodchenkov, former director of the Moscow anti-doping laboratory, to the FSB, the Russian security service, dating from January 2015, a month after allegations of systematic doping among Russian athletes were aired in an explosive German television documentary.

“Of particular danger,” says the report, which is inexpertly translated, “are those samples of urine and blood from the last Olympic Games stored up in the basement storage laboratory at the University of Lausanne.

“If you now reanalyzed with the help of new instruments Beijing samples – it will be a disaster.

“For example from 1990 to 2000 – previously oralturinabol could only be determined within five to seven days use, in 2015, the new sensitive instruments can determine it four to six months.”

The predicted “disaster” has now unfolded.

The IOC has re-tested at least 1,243 samples from the Beijing 2008 and London 2012 Summer Olympics.

These appear to have yielded 98 retrospective positives (or provisional positives), equivalent to just under eight per cent.

The piecemeal way in which details have been revealed has not made analysis easy, but a list of positive findings just supplied to me by the IOC reveals no fewer than 27 Russians among 73 athletes caught this year by Beijing and London re-tests.

Another list of 136 recent rule violations compiled by the OlympicStats blog included 64 relating to turinabol, the testosterone derivative that was the principal drug used in the state-sponsored doping programmes of the defunct German Democratic Republic.

OlympicStats has also worked out that 82.7 per cent of 104 cases it has traced since April “come from nations from the former Soviet Union”.

Does this then enable us to conclude that roughly four out of five drug cheats operating in Olympic sports in recent years have represented countries formed as a consequence of the USSR’s disintegration?

In a word, No.

Beyond the broad guidelines revealed by the IOC in May and July – specifically, that a first wave of re-tests was aimed at athletes who might line up at Rio, and a second, at Beijing and London medallists, with two further waves to follow - we have little hard information as to whose stored samples have been re-tested and whose haven’t.

All told, just under 1,900 Olympic medals were won in 2008 and 2012 combined.

So, even allowing for the fact that many were won by teams of widely varying sizes rather than individuals, an aggregate of at least 1,243 re-tests would indicate that a reasonably high proportion of those who won medals at these Games may have been re-tested.

Then again, quite a high proportion of those who did fail re-tests – 29 of 69 athletes I have traced back through IOC press releases, so 42 per cent - did not win medals.

The IOC has now told me that their Beijing reanalysis included samples from athletes from 89 National Olympic Committees (NOCs) and 16 sports.

It also says that the last two waves of Beijing re-tests revealed no new adverse analytical findings (AAFs).

“So…the majority of athletes with potential AAFs from Beijing were probably identified.”

Well, maybe; but here’s the thing:

What is to stop the IOC from producing a sport-by-sport and country-by-country breakdown of the 1,243 re-tests that we know have been conducted, along with a summary, in each case, of which substances have been re-tested for?

That would exhibit that much-trumpeted 21^st  Century sporting virtue of “transparency”; it would give everybody a much more detailed picture of where we stand; and I cannot for the life of me work out what, other than the relatively small cost of compiling the information, would be the downside.

After all, the samples in question are already procured and secured; if one assumes that the lab staff are honest and upright, as they must be for any anti-doping system worth its salt to function, it is not as if the donors can do a great deal to alter the course of events.

Actually though, there is a bigger point. I would argue that the whole system of dealing with these stored samples should be changed.

I can quite see the logic of target testing in day-to-day anti-doping operations, where resources are finite (not to say inadequate) and pressure is high to secure the maximum bang for the anti-doping buck.

But retroactively? The only rationale that I can think of for establishing a hierarchy of which stored samples are to be re-tested and which not is if you know you will not have the resources to re-test all of them.

And frankly, the current failure rate among these Beijing and London samples is so elevated, even if the last two castings of the net came up empty, that money really should be made available for every single one of them eventually to be re-tested to the maximum extent possible.

The IOC puts the cost per test at some $700 (£554/€657), making the potential price-tag for re-testing all 4,700-odd Beijing samples about $3.3million (£2.6million/€3.1million) – by no means negligible, but equally not excessive given the huge flow of funds pouring into the Movement nowadays.

I can understand and acknowledge that you do have to be selective, and therefore intelligent, about what you re-test for: as that Rodchenkov document put it, in its rather memorably broken English, “all methods can not be applied, just not enough urine volume, there remains 20-30 mL total”.

The timing of the re-test may also be regarded as a judgement call: you have to wait a certain time-span for detection methods to have improved sufficiently to make re-testing worthwhile.

But delaying more than about six years equally seems rather pointless, given the proportion of the original donors who would have retired from competing by then.

The IOC’s position on all of this is as follows:

“The amount of stored urine is limited, so we do not want to use it too soon (before new tests are developed) unless the intelligence for a particular new test in a particular group of athletes means that it is worthwhile.

“This is the case for a number of London samples thanks to the new test for steroids (long-term metabolites).

“Also the testing is expensive…so it makes sense to do it where there is a reasonable chance of success…

“New tests for substances other than anabolic steroids may be developed in the next three years…so unless there is a good reason, we want to keep samples until nearer to the eight years.”

All in all, I can think of no good reason why every stored sample should not undergo re-testing within eight years of collection at the very most, nor why a database should not be assembled enabling the public to compare results NOC-by-NOC, sport-by-sport.

I am not calling for the distribution plans for retrospective tests to be published, but for a detailed tally of how many re-tests have been carried out by country and by sport – and for what – to be made available after the event.

It should also be made explicitly and inescapably clear that those sports with the worst re-test records will get a big black mark against their name when it comes to working out the sports programme for future Games.

I would furthermore argue that if we ever get an independent global testing authority, responsibility for re-testing these stored samples should be handed over to it.

Just because the IOC, largely, pays the anti-doping piper, by dint of having the most valuable marketing and media rights, it does not make it ideal practice for it, the IOC, to exert such a high degree of control over the re-testing of samples taken at its events.

In summary then, this battery of tens of thousands of stored samples is a worthwhile tool; if utilised to best effect, in addition to acting as a deterrent, it could enable us to map the recent past of performance-enhancing drug use in Olympic sport more accurately than has so far proved possible.

But the scope of re-testing ought to be comprehensive: all 4,770 Beijing samples should have been re-tested by now, with outcomes summarised by country and by sport in a transparent way.

If money is an obstacle to this happening, then it shouldn’t be.

The problems at Rio will leave a few unanticipated gaps for future re-testers.

As stated by the report of the Independent Observers:

“The IOC specified that the top five finishers in every event were to be tested.

“However, this was mainly focused on high- and medium-risk sports, and did not occur at every event.

“(On some occasions it did not occur due to a lack of sufficient doping control personnel at the venue in question.)”

But a total of more than 4,800 samples were, nevertheless, gathered.

And finally, sooner rather than later, control of the samples in their Lausanne depository should be handed to an independent testing authority.