NORTHAMPTON, ENGLAND - DECEMBER 18: Dan Carter of Racing 92 looks on during the European Rugby Champions Cup match between Northampton Saints and Racing 92 at Franklin's Gardens on December 18, 2015 in Northampton, England. (Photo by David Rogers/Getty Images)

Traces of steroids have been found in the urine of former All Blacks Dan Carter and Joe Rokocoko, a leading French news source has reported.

French newspaper L'equipe reported that abnormalities were detected in the urine of Carter and Rokocoko in a test taken following the final of the French Top 14 rugby competition in June.

Athletes can have therapeutic use exemptions for steroids and other banned substances.

Their manager from Essentially Group, Simon Porter, told New Zealand Media and Entertainment (NZME) the players did have the correct exemption to use the banned substance.

The test was conducted by the French anti-doping agency, Agence Francaise de Lutte Contre le Dopage.