Berlin - European 10 000m champion Morhad Amdouni insisted Thursday that he is not involved in doping, slamming suspicions against him as an attempt to "dishonour" his name.
France's anti-doping agency said it was "fully aware" of "suspicions and allegations" of doping surrounding 31-year-old Amdouni.
"This is nothing, there are no facts," the runner told AFP.
Alarm bells over the French athlete absent from the ongoing World Championships in Doha were sounded by German television channel ARD, which has been investigating the athlete.
ARD reported it had seen messages on the social media chat service WhatsApp from a doping products supplier demanding payment from Amdouni for banned blood booster EPO and growth hormone supplement.
The German media outlet said on its website: "ARD's 'doping' editorial team has strong suspicions against France's Morhad Amdouni.
"During our investigations, one of the informants received a death threat" from Amdouni's entourage, the channel said.
However, Amdouni hit back at the allegations.
"This report tries to dishonour me, I have nothing to do with it, it's nothing, there are no facts, it's unbelievable.
"I know that my performances have created doubts among people," added the Corsican athlete who became European 10,000m champion in Berlin in August last year.
He then went on to run a first marathon in Paris in April where his time of 2hr 09min 14sec allowed him to qualify for the 2020 Olympics in Tokyo.
"The person (who sent the WhatsApp message) is someone I don't really know. I only saw her once during a jog. When I received her message I blocked her."
The French anti-doping agency said they are aware of the allegations.
"We are fully aware of the information published by ARD and suspicions and allegations targeting Mr. Morhad Amdouni," the organisation said.
The agency "will continue working in confidence... Judicial investigation time does not coincide with media exposure."
The French Athletics Federation told AFP it was taking the doping allegations "very seriously" but said that it had heard of no specific violations.