When Javed Nawaz arrived in Washington last month, he exchanged coded identification with a fellow Pakistani staying at the L'Enfant Plaza Hotel, using the serial numbers on Pakistani currency, according to the court statement of a federal Drug Enforcement Administration agent.

The man then gave Nawaz a five kilogram package containing a white powder, which the man said was pure heroin and which Nawaz carefully hid inside a garment bag, the agent, Judith K. Young, said.

At that point, DEA agents who had captured the exchange on videotape arrested Nawaz, culminating an elaborately planned sting operation that had begun in Pakistan two weeks earlier.

Authorities there seized five kilograms of heroin destined for delivery in Washington, according to the agent.

Before he came to Washington Nawaz had exchanged code names with his countryman by telephone, and he provided more identification upon arrival, the agent said. Having finished their exchange, the two were talking about the current price of heroin, the agent's court statement says, when DEA agents arrested him.

Yesterday the 30-year-old Nawaz, who has been living in the Chicago area for the past four years, was indicted here by a federal grand jury.

He was charged with seeking to distribute heroin, which the DEA said had a street value of more than $20 million.

Nawaz is being held without bond. When he was arrested, he had an airplane ticket to go back to Chicago that night.

In papers filed at a detention hearing last week, the DEA disclosed that the powder Nawaz received wasn't heroin at all but a mixture of flour and sugar.

The five kilograms of heroin had been seized by authorities in Pakistan two weeks earlier, the DEA said, but when they learned it was en route to someone in Washington whose identity was unknown, the DEA and the Pakistanis set up the long-distance "sting."

"This is the kind of thing we hope to do more of," said U.S. Attorney Joseph E. diGenova. "We want to interdict the drugs in their country of origin and then find out who their connection is here."

If it had been heroin, the five kilogram package would have been one of the largest amounts of the narcotic ever sold here, prosecutors said, though its ultimate destination appears to have been Chicago.

According to court papers, Nawaz is an illegal alien with deportation orders pending in Chicago.

The court papers say he lives in Calumet, a Chicago suburb, with his wife and young son and owns a chain of five sandwich shops around Chicago as well as additional shops in California.

In the order detaining Nawaz without bond, U.S. Magistrate Patrick J. Attridge said his success in opening so many sandwich shops could only be accounted for by access to "substantial financial resources of an unexplained nature."

The expansion "was not likely attributable to the profits from . . . the original sandwich shop alone," Attridge wrote.

Under the four-count indictment, which also includes charges of interstate transportation in aid of unlawful activity and two counts of unlawful use of a telephone, Nawaz faces a maximum penalty of 33 years in prison and $320,000 in fines if he is convicted.

In the court papers, signed by DEA agent Young, the identity of the Pakistani who made the delivery of the phony heroin is not disclosed.

Last week the U.S. District Court's Chief Judge Aubrey E. Robinson Jr. affirmed Attridge's order holding Nawaz without bond.

Attridge directed the D.C. Department of Corrections to provide Nawaz with a diet that does not contain pork, which Nawaz requested because of his Moslem religion.