Along with two others, Carter was the target of an investigation after testing positive for corticosteroids.
Carter, fellow former All Black Joe Rokococo and Argentinian winger Juan Imhoff were the target of an investigation after testing positive for corticosteroids following last season's Top 14 final.
However, they had already been found innocent by the medical commission of the French Rugby Federation (FFR) in October and now the French Anti-doping Agency's announcement brings the affair to a close.
"We are delighted with the decision rendered by the French Anti-doping Agency," said Racing in a statement.
"This whole pseudo-affair has cast scorn on our players and our club, partly ruining the start of our season.
"The innocence of Dan, Juan and Joe merits the same degree of attention as the suspicions they had been placed under."
The original dope tests, ordered by the French anti-doping agency (AFLD), found traces of corticosteroids, which can be used against pain, inflammation or allergies.
The substance is illegal when taken orally or injected in either the blood or muscle, unless accompanied by a Therapeutic Use Exemption (TUE).
Racing had always denied all wrongdoing, saying the substance was administered by an "authorised method" several days before last June's Top 14 final -- in which Racing beat Toulon in Barcelona -- and there was no need for a TUE.