The May 19 rematch between D.C. boxer Lamont Peterson and Amir Khan has been called off in the wake of this week’s news that Peterson tested positive for a banned substance.

After testing positive for a banned substance, D.C. boxer Lamont Peterson admitted yesterday to taking testosterone pellets as part of a medical treatment.

Their last bout ended in controversy, and now the May 19 rematch between D.C. boxing phenom Lamont Peterson and Amir Khan may not even happen—ESPN is reporting that Peterson tested positive for synthetic testosterone after a test conducted in early March.