Newspaper L'Equipe reported that the pair, along with winger Juan Imhoff, tested positive for corticosteroids before playing in June's Top 14 final.
Racing say the case relates to "treatment by an authorised channel".
They added: "We're on the side of law, ethics and love of a clean sport."
The statement came after Carter and Rokocoko's agent told the New Zealand Herald he had assurances "all the documents around TUEs were in place".
TUEs allow sportspeople to take prescribed medicines - which are otherwise be banned for their performance-enhancing properties - if there is a medical need.
"As far as I know today, there was no request [for TUEs] made ahead of time, but people are allowed to regularise these things after the event," French Sports Minister Patrick Kanner said on France Info radio.
Fly-half Carter, 34, and winger Rokocoko, 33, scored 20 points between them as Racing Metro beat Toulon 29-21 in Barcelona.
Argentine wing Imhoff, who has scored 21 tries in 35 Tests, was also part of the starting line-up at the Nou Camp.
Carter, man of the match in the Top 14 final, played 112 Tests for New Zealand and was part of the All Blacks side which won the 2015 Rugby World Cup.
He is widely regarded as one of the greatest players in the history of the game.
Rokocoko scored 46 tries in 68 Tests between 2003 and 2010.
French side Racing 92 say former All Blacks Dan Carter and Joe Rokocoko did not have therapeutic use exemptions (TUEs) for "anomalous" drugs tests but insist the players have not done wrong.