Butch Reynolds, the 400-meter world-record holder, acknowledged...

Butch Reynolds, the 400-meter world-record holder, acknowledged that an irregularity has surfaced in a routine drug test he took after a competition in Monte Carlo on Aug. 12.

“There’s a problem with the A sample,” said Reynolds, the 1988 Olympic silver medalist. “There’s no reason to be concerned. It’s just a formality, probably. If I was guilty of something, I’d be more concerned.”

A drug test urine sample is split in two parts, A and B. If the A sample is found to be positive, the B sample is tested. Only if both samples are positive is the athlete declared to have failed the drug test. Test have been thrown out on technicalities if the test procedures have not been properly followed.

It is believed the Reynolds’ matter is being handled within an appeals committee of The Athletics Congress, the national governing body of track and field. A TAC spokesman had no comment.

Reynolds would not reveal the nature of irregularity--whether the sample was positive or there was a breach in the test procedure. Reynolds set the 400-meter world record of 43.29 seconds in 1988.