Encke's positive result, though, is a disaster all by itself. It casts doubt on a whole season of flat racing and requires an asterisk to be placed next to the final classic of 2012.
Though the horse was clean in that race, the fact that he had steroids in him at the start of this season will raise valid suspicions about what he might have been given last year.
The so-called Coolmore mafia, whose trainer is Aidan O'Brien, must be tempted to exact the maximum PR victory from Godolphin's shame.
Even if there is no clear evidence of skulduggery when Camelot set off for the final leg of the Triple Crown after winning the 2000 Guineas and Derby, the details of the Doncaster race are under intense scrutiny.
Camelot, the 2-5 favourite, was the standard bearer for the Coolmore operation.
John Magnier, one of his owners, claimed to be motivated by a romantic urge to see another Nijinsky grace the turf.
Had Camelot prevailed then O'Brien would have become the first trainer to win all five British Classics in a single season.
In the race Camelot was held at the back of the field by his jockey Joseph O'Brien, and encountered traffic problems in the home straight. Encke, who ran on the orders of Sheikh Mohammed, Godolphin's owner, got first run on Camelot and won by three-quarters of a length: still a narrow margin in a 2800m contest.
Camelot's defeat was blamed partly on his hard race in swampy conditions in the Irish Derby.
After the race Al Zarooni said: "I thought Camelot would catch us as I remembered the way he quickened in the Derby, but I knew Encke was tough and would keep going."
The 2012 Leger is entering the realms of infamy. This was the race that Frankie Dettori says caused him to dabble with cocaine to lift his spirits after the Encke ride was assigned to Mickael Barzalona, his rival in the Godolphin camp.
Dettori's subsequent decision to ride Camelot in the Prix de l'Arc de Triomphe hastened the end of his relationship with Godolphin. Dettori has yet to ride again after his six-month ban for testing positive for cocaine in France.
Again there is no evidence of a conspiracy to stop Camelot heaping glory on the Coolmore operation at Doncaster but the BHA now needs to retrace its steps and re-examine Encke's dope tests in 2012.
The BHA says he was tested after two of his four races: at York on August 22 and again after the St Leger on September 15. Clarification is needed on the steroids for which Al Zarooni's horses tested positive and how long they can stay in a horse's system. That information is vital to assess whether an illegal substance could have been administered to Encke between August 22 and September 15 without showing up in the second of those tests.
This is the kind of rigorous investigation racing needs if it is to restore confidence in an industry that has been shaken by race-fixing and now doping scandals. The clean bill for Saeed bin Suroor's yard is the welcome part. It shows the problem to be confined to Al Zarooni's Moulton Paddocks stable, which Bin Suroor is now clear to add to his existing stock.
But that brings only fleeting relief. The scale of Al Zarooni's cheating only accentuates the need to find out who, if anyone, assisted him.
His appeal against an eight-year ban from the sport could yet bring new revelations, assuming he proceeds with it.
The BHA, whose zero-tolerance policy on performance enhancing drugs is to be applauded, has acted decisively so far, but must avoid the impression of cosying up to Sheikh Mohammed and Godolphin to stop them fleeing British racing.
Sheikh Mohammed himself should volunteer to be interviewed about Al Zarooni.
Turning on his heels when questioned on television at Newmarket will not repair the damage to Godolphin's reputation.
The 2012 St Leger, meanwhile, may be beyond rescue. Camelot's doomed Triple Crown mission will always be clouded in doubt.
The damage is spreading.Telegraph Group Ltd
