The trio of Racing 92 imports were cleared last October by the French Rugby Federation after traces of corticosteroids were found in tests following the Top 14 final in Barcelona last June.
But Le Monde has reported that the French anti-doping agency, The College of the AFLD, now wants a please explain from the players over the incident.
The French newspaper reported the development was "not rare".
When Le Monde approached Racing 92 about the reported development, the glamour Paris club refused to comment.