The newspaper said the 2016 report also accused coach Alberto Salazar of abusing prescription medicines for his athletes at the Nike training centre in Oregon.
Attempts by Reuters to reach Salazar for comment were unsuccessful. Salazar issued a lengthy and detailed denial of similar allegations in 2015.
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The Sunday Times said the report had been leaked by the 'Fancy Bears' hacking group which has previously leaked medical and doping-related documents.
USADA on Saturday confirmed to Reuters the documented cited by the Sunday Times appeared to have been leaked but would not comment on the report's conclusions or any accusations against Salazar.
"USADA can confirm that it has prepared a report in response to a subpoena from a state medical licensing body regarding care given by a physician to athletes associated with the Nike Oregon Project," USADA Communications Manager Ryan Madden said in an email to Reuters.
"It appears that a draft of this report was leaked to the Sunday Times by the Russian state-affiliated hacker group known as Fancy Bears.
"We understand that the licensing body is still deciding its case and as we continue to investigate whether anti-doping rules were broken, no further comment will be made at this time."
The Sunday Times said that Farah and other athletes coached by Salazar were given infusions of a research supplement based on the chemical L-carnitine and that one coach who was given a high dosage said that it was as effective as illegal blood doping, according to the report.
It said Salazar also emailed disgraced cyclist Lance Armstrong touting the benefits of L-carnitine.
Salazar, a Cuban-born American marathoner who has worked with Farah since 2011, was accused of violating anti-doping rules in a BBC documentary in 2015, including allegations he had given 2012 Olympic 10,000m silver medallist Galen Rupp the banned anabolic steroid testosterone.
Farah was exonerated by UK Athletics who found no impropriety on his part after receiving the initial findings of a review into his relationship with Salazar.
The current Sunday Times article says that, according to the leaked document, Salazar took “egregious risks” and abused prescription rules by persuading Farah to take potentially dangerous doses of permitted vitamin D prescription drugs believing it would boost his performance through increased testosterone levels.
Farah’s British doctors intervened because they were concerned about the effects on his health, the paper said, citing the leaked USADA report.
At last year’s Rio Games, Farah became only the second man to retain the 5,000m and 10,000m Olympic titles.
The hackers have previously published data on athletes gained from the World Anti-Doping Agency (WADA) administration and management system via an account for the Rio Games.
In October, USADA chief executive Travis Tygart labelled Fancy Bears "con artists" and said their aim was to "distract from the real issue of (Russia's) state-sponsored doping".
Fancy Bears is one of two hacking groups accused in June of hacking the Democratic National Committee's (DNC) computer network in the United States.
CrowdStrike, a firm hired by the DNC to respond to those attacks, said in June that Fancy Bears was probably working on behalf of the Russian military.
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29/04/2021 AT 10:41