Federal prosecutors on the trail of suspected Washington-area drug profiteers seized a $400,000 Fairfax County estate yesterday, claiming that it was purchased with money made on the sale of marijuana.

The seizure is one of the first in the Washington area under a two-year-old federal drug statute permitting the government to foreclose on property allegedly bought with the fruits of drug trafficking, a law enforcement official said. Similar seizures have been carried out in Florida, Texas and other areas where alleged drug smuggling has flourished, according to the official.

Prosecutors in Alexandria refused comment yesterday on the action, which was disclosed when they filed a lawsuit in federal court there supporting the government's claim to the property. Court documents in Alexandria and Fairfax County described the seized property as a 10-room, two-story residence with swimming pool on 10 wooded acres at located at 3301 Burgundy Rd., south of Alexandria.

The suit, signed by Assistant U.S. Attorney Karen Tandy, said prosecutors believe the tract, worth an estimated $400,000, was purchased July 6, 1979, with "proceeds traceable to unlawful exchanges" of money for marijuana.

A separate filing by Tandy in the Fairfax County land records named parties affected by the government's action as RealCon Investments Inc., which currently holds title to the estate, and Leon Durwood Harvey of Fairfax.

Harvey was convicted in a widely publicized drug ring case in 1974 in U.S. District Court in Alexandria in which prosecutors claimed the ring had concealed drug profits by investing in legitimate businesses. He has recently been named as the primary target of a continuing federal grand jury tax and drug investigation.

In that trial, a key prosecution witness testified that the drug ring -- for which Harvey allegedly acquired hundreds of pounds of marijuana -- invested drug profits in a Texas shrimp boat operation, a produce business, a motel and a farm in West Virginia where drugs were stored.

Harvey was convicted Oct. 11, 1974, on conspiracy and interstate travel in aid of racketeering charges and sentenced to two three-year prison terms, to run concurrently. After a long series of motions and appeals, Harvey went to prison.

Records showed the secluded property was sold two years ago by a couple living in Hawaii to a Massachusetts firm called Claw One Inc. for $243,825. It was resold to RealCon soon after, in December, for $265,000. Prosecutors placed the tract's current value at $400,000.

Efforts to reach RealCon, Claw One, and Harvey's lawyer were unsuccessful. The office of the secretary of the commonwealth in Boston said Claw One gave its address in corporate records as Leominster, Mass., but attempts to find a telephone listing for the company there were unsuccessful.

Yesterday's filing was the latest development in a fractious legal struggle surrounding attempts by the government, beginning in February, to present evidence to the grand jury in support of Harvey's possible indictment.

District Judge Albert V. Bryan Jr. has jailed two potential witnesses who refused to give grand jury testimony in the case despite grants of immunity from prosecution.

Alexandria criminal defense lawyers also were angered after prosecutor Tandy succeeded in compelling Harvey's mother and wife to testify to some aspects of the investigation before the grand jury. In addition, defense lawyers involved in the case complained that federal prosecutors had improperly shared some grand jury testimony with the Internal Revenue Service, the FBI and the Drug Enforcement Administration for further possible prosecution of Harvey. The U.S. attorney's office in Alexandria has denied any impropriety.

All of that led to a complaint by Harvey's wife, filed with the Justice Department, that Tandy was guilty of prosecutorial misconduct, a charge the department said it investigated and found "completely groundless."

District Judge Oren R. Lewis recently denied a defense motion that the grand jury be disbanded on similar grounds.

The latest in the flurry of defense maneuvers -- several of which have been appealed to a federal appeals court in Richmond -- involves an attempt by Tandy to subpoena records belonging to Harvey's lawyer, J. Flowers Mark of Alexandria.

Mark, claiming communications between client and lawyer are privileged, asked Lewis earlier this month to quash the subpoena. Lewis denied the request, and Mark is now scheduled to appear before the grand jury sometime next week.