A high-ranking diplomat in the Chad Embassy here said yesterday that he traveled earlier this year to Pakistan at the request and expense of two Pakistanis arrested on heroin-smuggling charges, but that he was not involved in any illegal drug operations.

Ousman Abdoul, 34, first secretary at the North Central African nation's embassy, said that he only made the trip in May to the Golden Crescent area, source of much of the heroin now being smuggled into the United States, because the Pakistanis persisted in their request that he go and because he did not have much embassy work to do at the time.

The two Pakistanis, Hizbullah Kahn, 26, and Mohammad Nisar, 22, have told federal narcotics investigators that Abdoul is one of two Chad diplomats here who allegedly assisted them in their heroin-smuggling operation, according to a source familiar with the investigation.

"This is not true," Abdoul said in a telephone interview yesterday from New York, where he is attending the United Nations General Assembly session. Abdoul is one of three diplomats assigned to the Washington embassy. "For the moment," he said, "I'm a little bit disturbed" about the allegations implicating Chad Embassy officials in illicit drug activities.

"First of all I didn't know [the two Pakistanis]. They just stopped by my house one day about six or seven months ago," he said.

Abdoul said he told the men he did not want to get involved with them, but that they repeatedly visited him at the embassy, which was then housed in a suite at the Watergate office building at 2600 Virginia Ave. NW. He said the Pakistanis told him they knew that Chad was in the midst of a civil war, and that he and other dilomats here might be short of money.

"I'm a diplomat. I'm not going to deal with people like you," Abdoul recalled telling them. "I did not ask them ever for money." But when they gave him a letter from Kahn's father inviting him to Pakistan, Abdoul said he decided to make the trip there "since we didn't have a lot of work to do."

Abdoul said that Kahn's father, who is in the importing and exporting business in Pakistan, escorted him around while he went on sightseeing trips during his three days in that country. Kahn's father gave him only two items to bring back to the United States -- a letter and a package containing a stone, Abdoul said.

Abdoul said upon his return to the U.S. he gave the letter to Kahn, but he kept the package with the stone and it is still at his Silver Spring home. hKahn then asked him to make another trip to Pakistan within two weeks.

"To do what?" Abdoul said he asked Kahn. "The only thing your father gave me was this package." Abdoul said when he refused to return to Pakistan Kahn became very upset. He said he never heard from Kahn or Nisar again.

Prosecutors, who said they were upset about the premature disclosure of the investigation, declined to comment on the probe yesterday.

Assistant U.S. Attorney Daniel J. Bernstein said in open court Monday that the two Pakistanis had close ties with an official at an unnamed embassy here. The officials, Bernstein said, indicated that they could provide sanctuary for them at the embassy if they became entangled with law enforcement officials. Bernstein did not identify the embassy involved, but other sources have confirmed that the diplomats allegedly involved are high-ranking officials at the Chad Embassy.

The other Chad official allegedly named by the Pakistanis could not be reached for comment yesterday.

According to court records both Kahn and Nisar, who are being held under $1 million bond each, live in an apartment at 4849 Connecticut Ave. Nw. They told court officials they are employed as gem dealers.

Prosecutors said the two allegedly have access to multiple quantities of heroin in other areas of the United States, worth millions of dollars in street sales.