Marc Farry today became the first European Tour player to return a positive drugs test.
However, the Frenchman seems certain to escape censure as he had been on a medically prescribed drug used to treat a wrist injury.
Farry was one of six players who undertook the voluntary test during the French Open in Paris in June.
The other five players - Graeme McDowell, Philip Golding, David Howell, Peter O'Malley and Francois Delamontagne - returned negative samples.
The 44-year-old's test, conducted by the French Sports Ministry, revealed traces of a banned substance, Prednisolone, but it is a drug not deemed to be performance enhancing.
Farry, who missed the cut in the Nordic Open today, is confident of being exonerated when he meets the French Federation on September 15th.
He said: "I had received a cortisone injection and took some anti-inflammatory pills about three weeks before the French Open and informed the doctor in attendance of this fact when we went into the room for the drug test. I asked if that would present a problem and he said it would not.
"On the form I filled in with my name and occupation there was also a little space for the doctor to make comments. He should have mentioned that I told him I had an injection about 20 days before the test and because he didn't all this has happened."