Lawyers for Peter Bol say Sporting Integrity Australia should drop its investigation into the Australian athletics star after two independent labs cleared him of using synthetic EPO.
Bol — who finished fourth in the 800 metres at the Tokyo Olympics in 2021 — was provisionally suspended from the sport in January after it was revealed his A-sample had come back positive for EPO.
His B-sample, when tested by the World Anti-Doping Agency, returned an "atypical" result and that allowed him to return to the sport.
Bol has maintained his innocence throughout the process, but said the initial result being made public has permanently tarnished his reputation.
After that B-sample came back, Bol's team sent the sample to two independent laboratories that specialise in this sort of testing.
EPO, or endogenous erythropoietin, is a naturally occurring hormone in the human body that promotes red blood cell production, but synthetic EPO has been used by athletes — most infamously cyclists such as Lance Armstrong — to increase stamina.
A letter from Bol's lawyer, Paul Greene, said the testing at the Australian Sport Drug Testing Laboratory (ASDTL) was marred by "inexperience and incompetence … [which] led to an incorrect determination" of the A-sample.
The letter said the independent testing "never showed any presence of synthetic EPO".
The ASDTL said it is the country's peak analytical anti-doping lab and the only WADA-accredited sports testing laboratory in the Oceania region.
"Its staff are experts in their field," an ASDTL spokesperson said.
"The laboratory has been carrying out EPO testing for over 20 years.
"The laboratory conducts this testing on behalf of Sport Integrity Australia (SIA), and it follows WADA's technical specifications when conducting tests."
SIA is still conducting an investigation into Bol's samples, but Mr Greene said the SIA was not really investigating and should publicly apologise.
"They have a duty under the rules to come out and say: 'There's nothing here'," Greene said on Nine's Today program.
"Say you're sorry."
The Australian national championships start in Brisbane on Thursday and Bol said he would love to be competing there, but will instead refocus on the world championships in Hungary in August.
"I don't think there is a single Australian athlete who won the 800m four times in a row and I was supposed to be there," he told Today.
"It is disappointing. We will move on. We have world champs, heading to Europe, racing there.
"I would prefer to race in Australia and give the Australian public, I guess, time on the track. Because they have supported me the whole way."
Greene has given SIA nine days to respond.