According to French sports newspaper L'equipe, the two Racing 92 players submitted tests showing traces of banned corticosteroids following the final of the French Top 14 rugby competition on June 24.

A third player, Argentinian Juan Imhoff, was also implicated in the "anomalous" results following testing by the French Anti-Doping Agency (AFLD).

Carter and Rokocoko's manager Simon Porter has claimed the duo were notified of the results a few weeks ago but had done nothing wrong.

"They were told they had nothing to worry about, that all of the exemptions and declarations were in order so the boys have been pretty relaxed about it," he told the New Zealand Herald.

"They're not enjoying the attention that this brings but they're pretty relaxed because they've been given the assurances that they've done nothing wrong."

Porter, who works for Essentially Group, plans to now contact Racing 92 in order to "get some clarity".

He suggested that Carter had used a corticoid for treatment of a calf injury, while Rokocoko was recovering from a knee injury.

Racing 92 beat rivals Toulon 29-21 in the Top 14 Final at the Nou Camp in Barcelona as World Rugby Player of the Year Carter produced a man of the match performance.

The use of TUEs continues to draw attention after the publishing of leaked information obtained by hacking group Fancy Bears'.

They are permitted when athletes are required to take otherwise banned products for medical purposes.

Concerns have been raised that some athletes may be using them as an excuse to obtain a performance-enhancing benefit.

Use of some corticosteroids is fully if injected into a joint; used on the skin, or taken nasally.

But a TUE is required if taken orally, injected into a muscle, or taken by suppositories.

The French Rugby Federation has a 40 day period to rule on whether use of the substances can be justified on medical grounds after being notified of the failures.

Disciplinary proceedings will be carried out otherwise.