Four years ago a Northern Virginia art importer named John E. Berkey approached some of the nation's largest drug companies and asked for their help.

A baldish man in his 60s described as "pugnacious" and "flamboyant" by one acquaintance, Berkey, then an Alexandria resident, outlined a plan for funneling drugs to the world's sick and needy through two Washington-based charities he had set up.

The pharmaceutical companies, including such industry giants as Ortho, Pfizer and Hoffman LaRoche, responded generously, donating or selling at discount rates at least$10 million worth of drugs, vitamins, contraceptives and medical supplies for Berkey's mission of mercy.

But skeptcism crept in. Ortho company officials complained that someone had approached its customers with a "knock-down price" on contraceptives and that the lot numbers matched those sold at a discount to the Berkey charities.

Managers of a warehouse in New Windsor, Md., 35 miles north of Washington, became wary when the charity sent trucks to pick up supplies instead of transferring them directly to the Baltimore docks for shipment overseas.

Now, after a two-year probe by a Justice Department strike force, prosecutors are presenting evidence to a federal grand jury in Maimi, alleging that Berkey's charities may have had secret beneficiaries.

Instead of shipping the supplies overseas, according to an FBI affidavit, Berkey allegedly resold the stocks through a chain of eight interrelated Florida pharmaceutical wholesalers in a sophisticated operation that may have violated federal antiracketeering laws.

Only sketchy details have been disclosed in Miami, where stacks of records of the drug companies' dealings with Berkey have been subpoenaed. But sources close to the investigation said as many as 15 indictments are expected within the next few months.

Information about Berkey and his endeavors also is scant. The Washington area charities, Opus Christi America Inc., which once leased office space in the Watergate, and Church of God, World Missions Inc., are now defunct. Berkey's whereabouts are apparently unknown, although an Alexandria neighbor, Thomas Humphrey, said Berkey left the area in December 1976, saying he was off to Spain.

If FBI, Internal Revenue Service and strike force officials know, they are not commenting.

"We had been misled," said a spokesman for the New Jersey-based Hoffman LaRoche, which acknowledged it shipped about $250,000 worth of pharmaceuticals to Opus Christi (Latin for Christ's work). "It had always been our understanding that these products were shipped abroad. We inquired. It had obviously not been shipped overseas."

Another organization that severed its ties with Berkey was InterChurch Medical Assistance Inc., a Protestant charity in New York that helped line up supplies to be sent to the New Windsor warehouse.

"We were embarrassed," said Arthur Wilde, director of IMA. "We were not happy we unwittingly had embarrassed some of our friends and that the group was not who it was supposed to be."

Berkey's art business centered on Koriental Inc., a small, second-floor shop he ran at 4900 Leesburg Pike near Baileys Crossroads where he sold figurines and silk-screen imports, according to neighbors.

A manager of the George Washington University Club, a dining club for faculty and administrators, in 1971 and 1972, Berkey was "very pugnacious, very flamboyant," said an associate of the charities who asked not to be identified. The associate said Berkey owned two large cars, had lived for several years in Denmark and owned a condominium on Majorca, the Mediterranean resort off the coast of Spain.

"He thought everything he touched would make him a million dollars," said a woman acquaintance in Alexandria.

An Alexandria clergyman, the Rev. David Willetts of the Church of God, lived across the street from Berkey and lent his name to Berkey's endeavors. But Willetts pulled out of the venture when Church of God headquarters in Cleveland, Tenn., raised questions about the operation.

Willetts, who said he has twice been questioned by the FBI, declined to comment about details of the arrangement.A spokesman for the church's headquarters, which disavows any connection with the Alexandria charity, acknowledged it received three large shipments of goods from Berkey which it said were subsequently shipped abroad.

Philip Weinstein, a Florida pharmaceutical distributor named in an FBI affidavit, acknowledged in a telephone interview that he had purchased at least $3 million in drugs from Opus Christi, but said he did not know the organization was holding itself out as a charity and denied any wrongdoing.

"Berkey didn't tell us how he got the stuff and it wasn't for us to ask him," Weinstein said.