Sir Mo Farah stressed he has "never failed a blood test" following the release of hacked documents from the International Association of Athletics Federations (IAAF) which appear to show a blood test result from him and from 46 other athletes that caused initial suspicion and required further checking.
Others on the list include Sir Mo's training partner Galen Rupp from the United States and Kenya’s triple world 1500 metres champion Asbel Kiprop and 2017 London Marathon winner Mary Keitany.
Also on the list is Ireland’s 2013 world champion in the 50 kilometres race walk, Robert Heffernan.
Hackers Fancy Bears' published documents which appear to show Farah returned a sample for his athlete biological passport (ABP), which monitors blood levels over time, that needed further testing.
The data goes on to show Sir Mo was then cleared when his results were later viewed as "normal".
"We have never been informed of any of Mo's test results being outside of the legal parameters," said a spokesperson for Britain’s world and Olympic 5,000m and 10,000m champion.
"Nor has Mo ever been contacted by the IAAF about any individual result.
"It is totally incorrect and defamatory to suggest otherwise, and we will pursue any claims to the contrary through all necessary legal routes.
"It has been widely reported that previous leaks from this organisation have included false or altered documents and we have asked the IAAF to urgently look into the validity.
"Regardless, any suggestion of misconduct is entirely false and seriously misleading.
"Mo Farah has been subject to many blood tests during his career and has never failed a single one."
Sir Mo is currently preparing for what will probably be his last track races at the IAAF in London from August 4 until 13.
Fancy Bears' - thought to be a Russian hacking group - began releasing data last year and focused largely on naming those who had sought therapeutic use exemptions, which allow athletes to take banned substances for verified medical needs.
The IAAF revealed in April it was hacked by the group in February.
It said it believed this latest release of data is likely to be from the same hack but was "looking into" the matter.
Sir Mo has always vociferously denied ever taking performance enhancing drugs.
His coach since 2011, Alberto Salazar, is currently under investigation by United States Anti Doping and issued a 12-000-word open letter in 2015 denying accusations that he had violated anti-doping rules.
Heffernan expressed surprise at his inclusion on the list of names.
The Irishman's profile was deemed normal after further review by anti-doping authorities.
When contacted by the Irish Independent and informed that his name was on the list, Heffernan welcomed the concluding comment about his case, which stated his blood profile was "now flagged as normal with the last sample".
Heffernan said the probable explanation for the initial atypical finding was a test conducted moments after he awoke from hip surgery in April 2015.
The adverse result, he says, was due to the presence of hydroxyethyl starch - an ingredient used in an intravenous paracetamol infusion he received during the surgery.
He was notified of the finding at the time by the IAAF but was soon cleared of any wrongdoing after providing an explanation via his medical team.
The details of the incident were outlined in his autobiography Walking Tall, published last November.
"It's not suspicious," said Heffernan.
"This just proves everything is normal, so it's actually positive for me."