Three-time world champion Asbel Kiprop says he has given up trying to prove his positive doping sample was contaminated.
Kiprop, the Beijing 2008 Olympic champion and third fastest 1,500 metres runner ever, tested positive for erythropoietin (EPO) in the out-of-competition test in November 2017.
The Athletics Integrity Unit admitted last month it was "very disappointed" after confirming that the Kenyan had been given advance notice of the test, a breach of the anti-doping rules, but denied his allegations that drug-testers asked him for money.
Kiprop claimed he gave drug-testers money because he trusted the cash was not "anything to do" with the sample he provided on the day he tested positive for EPO.
In a Facebook post, Kiprop has maintained his innocence but added he did not have the finances to challenge the International Association of Athletics Federations (IAAF).
"I have let the struggle to prove my innocence go," he wrote.
"Not because I doped, but I take the sacrifice because I support the anti-doping campaign.
"I do not have money to meet legal fees and find qualified physicians who can give their opinion on my sample and discredit any possible unjust reason to why the sample resulted in an EPO finding.
"I'm financially weak to challenge my accuser, the IAAF, whom I have always worked hard for.
"However, I'm rich in truth and sincerity - this seems to mean nothing."
In a recent interview with BBC Sport, Kiprop reiterated his insistence that he was asked for money by the anti-doping officials and said he thought they wanted it "for fuel or tea".
The 28-year-old added that he had built up a level of trust with the drug-testers, who he claimed would text him to forewarn him that they were coming.
Kiprop originally came second at Beijing 2008 but was upgraded to gold when Bahrain's Rashid Ramzi failed a drugs test.
He added world titles in 2011, 2013 and 2015.
Earlier this week, UK Anti-Doping (UKAD) agreed a 12-month partnership with the Anti-Doping Agency of Kenya (ADAK) which will see the organisation provide advice, guidance and training to its counterparts in the East African nation at different points throughout the year.
UKAD’s medical programme officer, a senior testing officer and three doping control officers travelled to Nairobi on Monday (June 11) to lead a week-long training programme with the ADAK.
UKAD will be working with the ADAK to establish a Therapeutic Use Exemption Committee and will also provide training for its doping control officers.
The partnership comes at a time when Kenyan athletics is shrouded in scandal.
Last month, Michael Rotich, Kenya's athletics team manager at the Rio 2016 Olympic Games, was charged with alleged involvement in a doping conspiracy in the country.
According to The Star, Rotich, sent home in disgrace from Rio 2016 following allegations he took bribes to forewarn athletes about doping tests, conspired to unlawfully promote the use of prohibited substances to athletes in Kenya.