A federal judge in Alexandria refused yesterday to allow the release on bond of Robert B. Reckmeyer, who is accused of helping direct an alleged nationwide drug operation based at a secluded Loudoun County estate, concluding that "there is a high risk" that Reckmeyer would flee.

U.S. District Judge James C. Cacheris ordered Reckmeyer, 30, held without bond at the conclusion of a hearing at which the defendant sought to have his original bond of $500,000 reduced.

In three hours of testimony from federal and state agents, the judge heard that Reckmeyer began distributing drugs 12 years ago while attending Langley High School in Fairfax County, and that in recent years he purchased machine guns to protect his drug operation, which is believed to have earned him personal profit of more than $9.5 million.

One Virginia investigator testified that Reckmeyer bought 13,000 pounds of hashish on one occasion with $1,755,000 in cash contained in two suitcases.

Reckmeyer, who gave his address as 12900 Westbrook Dr., Centreville, is under indictment on 24 counts, including drug, firearms and tax violations, in connection with an alleged operation said to have distributed 293 tons of marijuana and hashish in the last decade.

He and two other men, including his brother Christopher F. Reckmeyer II, 33, who have not been apprehended, are accused of being the "kingpins" of the alleged operation. Twenty-six persons are under indictment.

Federal prosecutors say the operation used gem and Oriental-rug companies to "launder" its profits and was directed from Shelburne Glebe, Christopher Reckmeyer's 1,000-acre estate near Leesburg.

The brothers' father, William J. Reckmeyer, who is president of Inter-National Research Institute in McLean, said he had no knowledge that his son Robert might have been operating an illegal enterprise and that the indictment came as a surprise to him.

He testified he believes Robert Reckmeyer has the utmost respect for "the due process of the court."

Robert Reckmeyer's wife, Patricia, indicted on one drug and five tax law violation charges, sat silent in the courtroom, leaving from time to time to tend to their month-old child, whom a sister-in-law was holding in the hallway. Patricia Reckmeyer is free on personal recognizance so she can nurse the child.

John Dowd, the Washington lawyer representing Robert Reckmeyer, argued that his client would surrender "his passport and gun" if freed on bond.

But Karen P. Tandy, the assistant U.S. attorney prosecuting the case, told the judge that federal investigators had found Reckmeyer had in his possession over the last year false driver's licenses and birth certificates that he could use to obtain a new identity and flee the country.

Tandy alleged that as a "cost of his business" Reckmeyer paid for "new identities of any truck drivers who were arrested" during the delivery of marijuana and hashish.

She said he posted bail and supplied new identities to men who were arrested in the past, are now charged in the drug indictment and are fugitives. "Because of him Reckmeyer we don't know where they are today," she said.

Among the charges against Reckmeyer are that he bribed a grand jury witness, illegally possessed Uzi submachine guns, and bought drugs along the East Coast, storing them in Washington area "stash houses" and then distributing them.

Steven Staka, a special agent of the Virginia State Police, testified that Reckmeyer once gave an informant two suitcases filled with $1,755,000 in exchange for 13,000 pounds of hashish in Hilton Head, S.C. There, Staka testified, "Robert Reckmeyer directed 13 different drivers to load 13 pickup trucks with hashish."

Reckmeyer and nine others arrested as a result of the indictment are scheduled to be arraigned on Monday.