The Justice Department yesterday announced the indictment of 26 persons in connection with an alleged nationwide marijuana and hashish operation headquartered at a secluded farmhouse in Loudoun County and believed to have generated more than $100 million in profits.

U.S. Attorney Elsie L. Munsell said 293 tons of the marijuana and hashish are believed to have been distributed over the last decade. The proceeds from their sale were "laundered" through business firms in several states selling gems and Oriental rugs, she said. During a press conference at her Alexandria office, Munsell said Virginia state police troopers were diving into the private lake at the suspected headquarters near Leesburg searching for African emeralds and Thai rubies believed connected with the suspected drug operation.

The alleged drug ring began operating as early as 1974, according to Munsell, and smuggled marijuana from Colombia and Mexico and hashish from Lebanon.

Drugs were brought ashore in boats along the East Coast and stashed in warehouses and farms in several Washington-area locations, said Karen P. Tandy, the chief U.S. prosecutor in the case.

"Off-the-beaten-track farmhouses" are increasingly becoming centers of drug operations because of their remoteness and their distance from drug investigators centered on coastal areas, Munsell said.

The investigation was called Operation Flying Carpet and involved federal agents infiltrating the alleged drug ring, Munsell said.

The indictment says that at one point one of the suspects delivered $850,000 and 32 Oriental rugs to an undercover agent of the federal Drug Enforcement Administration in Northampton County on Virginia's Eastern Shore.

The indictments were handed up by a U.S. District Court grand jury in Alexandria last Wednesday, but were kept sealed until yesterday after search and arrest warrants had been obtained. The charges include illegal drug dealing, illegal possession of firearms -- including 10 Uzi machineguns and 800 rounds of ammunition -- and tax fraud.

At dawn yesterday, 120 state and federal agents began making arrests.

The Shelburne Glebe Farm, on Rte. 729 about four miles southwest of Leesburg, was seized as the suspected headquarters and the divers began to search the lake there. The results of that search were not known last night.

By evening, seven persons had been arrested, including one of three described as "kingpins" of the alleged operation -- Robert Reckmeyer, 30, of Centreville.

Reckmeyer and the two others -- his brother, Christopher F. Reckmeyer II, 33, of Leesburg and Bruce W. Thomason, 34, of Waldorf, Md. -- face drug and tax charges plus the charge of conducting a criminal enterprise which, upon conviction, can carry a sentence of life imprisonment without possibility of parole. Christopher Reckmeyer and Thomason had not been arrested by early last night.

All 26 suspects, many of whom live in Virginia, were indicted on the charge of conspiring to distribute marijuana and hashish, which carries a sentence of up to 15 years in prison and a $25,000 fine on conviction.

According to the 122-page indictment, Robert Reckmeyer is accused of paying an estimated $1 million for marijuana at a Springfield "stashhouse" on Hooes Road in December 1978.

The following year, the indictment alleges, he purchased between 7,000 and 8,000 pounds of marijuana at the Oak Lee Farm in Leesburg.

The indictment also says that much of the profit from the alleged drug transactions was "laundered" through Crancy Inc. and United Trade Inc., two Northern Virginia jewel trading companies owned by the Reckmeyer brothers.

The court is asked in the indictment to order the forfeiture to the government of a variety of the defendants' assets valued at more than (National Caucus of Labor Committees photo) Virginia.

The indictment charges several of the defendants with falsifying business invoices that grossly overstated company profits to conceal the transfer of drug profits.

"Movable valuables," including an 8.13-carat red Thai ruby, were used as "down payments" for drug shipments, Munsell said.