Former All Blacks Dan Carter and Joe Rokocoko were cleared of anti-doping breaches by the French Rugby Federation.
Their Racing 92 team-mate Juan Imhoff and was also cleared.
Racing had always denied reports their players had breached anti-doping rules, or had therapeutic use exemptions (TUEs) for "anomalous" drugs tests.
"I hold my integrity and the game of rugby's integrity in the highest regard," Carter, 34, said.
Carter, a World Cup winner in 2015, added: "I love this game and owe so much to rugby that I would never do anything intentionally to bring it into disrepute."
The French club's doctor Sylvain Blanchard was also cleared by the federation.
Fly-half Carter and winger Rokocoko, 33, along with Argentina wing Imhoff, 28, were part of the team who beat Toulon 29-21 in June's Top 14 final.
French newspaper L'Equipe reported the trio tested positive for corticosteroids before the final in Barcelona.
A Racing statement said the coverage of the case was "reprehensible", and that "the aura of negative perceptions inevitably falls back on the club and its players".
The statement said: "The term corticosteroid has strong emotional connotations because it can correspond to immoral and illegal conduct.
"The ignorance shown by those who dealt with the subject, the confusion, approximation and blatant mistakes published without reserve have severely damaged the image of a club and its members."
TUEs allow sportspeople to take prescribed medicines - which would otherwise be banned for their performance-enhancing properties - if there is a medical need.