Federal officials are investigating two lawyers they believe are behind-the-scenes masterminds of a major cocaine ring with multimillion dollar sales in the District of Columbia and its Virginia and Maryland suburbs, according to a law enforcement source.

The lawyers - one in Northern Virginia and the other in the District - "organized the deal, set it up, ran it and smoothed things over when problems arose," the source said.

The lawyers remain unidentified. But "they know we know who they are," said the source, who is familiar with a recent 10-month investigation of cocaine trafficking in the area. "It's a matter of time until we put everything together."

Five members of the ring were convicted Thursday in federal court in Alexandria of conspiracy and cocaine distribution charges growing out of the investigation. Now that the trial is over, the source said, the probe of the attorneys is in "high gear."

The source declined to say what the attorneys allegedly did to "smooth things over" for the cocaine dealers, or what type of practice the two lawyers are involved in. He did say one of the alleged members of the ring is a former police officer.

During the four-day trial, the jury heard testimony about an unidentified "big man" who allegedly gave orders to some of the ring's members. But, according to the source, the two lawyers were each regarded as "the big man" by the people they dealt with. The two attorneys "coordinated" drug sales in Virginia, the District and Maryland, the source said.

During the year-long investigation, which included undercover penetration of the ring and use of court-approved wiretaps, conversations with the two lawyers turned up on police tape recordings, according to the source.

"This investigation is definitely continuing," said a second knowledgeable source, "and there will be other indictments."

District Detective Michael E. Hubbard, a key witness in this week's trial, told federal Judge Oren R. Lewis in court Thursday that he learned from Alexandria police that defendant Michael F. Tillery had kept selling cocaine from his home in the city's Del Ray section since his indictment last May.

After the jury returned its guilty verdict, Lewis revoked bond and ordered Tillery and his four codefedants jailed. Sentencing is set for Aug. 10.

Officials said yesterday they also are investigating other allegations of criminal activity that surfaced at the trial, including the sale of stolen merchandise and the existence of a nationwide stolen-car ring.

The investigation includes information obtained by undercover agents that a car-theft ring based in Detroit would steal "any make or model new car equipped with any options you like" from new car lots in Michigan for a $3,500 fee, a law enforcement source said.

Tillery and a codefendant in this week's trial, Wayne McNair Hargrove, are among the subjects of the expanded probe, the source said.

According to trial testimony, Hargrove and Tillery both were driving stolen white Corvettes when they were arrested May 22 in connection with the cocaine investigation.

Hargrove and codefendant Antonio L. Perdix, who pleaded guilty to cocaine charges before this week's trial began, also have been indicted on cocaine-related charges in Detroit, according to officials. Perdiz was identified in pretrial hearings in Alexandria as the supplier of cocaine to the Washington group.

Officials also are investigating statements made in trial testimony that Hargrove earned a living by selling stolen goods, such as video tape recorders, expensive watches and jewelry, and did not sell cocaine, a source said.

Meanwhile, authorities here are monitoring the Detroit proceedings in order to learn more about the flow of cocaine between Detroit, Washington and other cities, including New York, Miami, Dallas and Los Angeles, several sources said.