A man under investigation in an Alexandria drug sales probe was identified yesterday by law enforcement sources as Pleasant A. (Pete) Lewis, an Alexandria health club owner.

Sources said that Lewis, 28, an owner of the Iron Works Gym on West Duke Street, is a friend of David B. Goldberg, a former Alexandria narcotics investigator. Goldberg resigned from the police force Aug. 7 after being asked to take a polygraph test.

Goldberg is among several competitive body builders who work out at the gym, and Lewis was among several people who learned this spring that they were the objects of a confidential investigation into drug trafficking, sources said.

Goldberg's resignation, first reported last week, brought to light an investigation into interstate drug sales being conducted by a Northern Virginia police task force. The continuing probe, which began early this year, has produced no charges against anyone.

According to sources, Lewis is being investigated by the task force in connection with two allegations: that he is involved with an interstate ring selling marijuana and cocaine and that he sold steroids to body builders who work out in the gym.

Lewis did not return telephone calls yesterday.

In April, sources said, a confidential informant told members of the task force that Lewis knew he was under investigation. The informant said he had been told that Goldberg had leaked information about the probe to Lewis.

The allegations were reported to the commander of Alexandria's vice and narcotics unit, Lt. Arthur L. Bratcher, but no one else in the department learned of the charges until late June or early July. Deputy Chief John Streeter has said that Bratcher violated department rules by not reporting the allegations sooner.

Alexandria police are investigating what prompted Bratcher's delay and whether the confidentiality of the drug probe was violated, according to Streeter. An attorney for Goldberg has denied that his client leaked information about the investigation.

The chairman of the Northern Virginia drug task force, Capt. William R. Edmonston of the Fairfax Police Department, declined yesterday to comment on the probe.