Alexandria City Manager Vola Lawson has ordered that Police Chief Charles T. Strobel not participate in a probe into alleged misconduct in his department and that police officials cease efforts to identify whistle-blowers who publicized the charges, according to city and law enforcement officials.

Concerned that the internal police investigation has been mishandled, Lawson stepped in this week to impose her own guidelines on the probe, officials said. The investigation was launched late last week, when questions were raised regarding the actions of a former narcotics investigator, David B. Goldberg, and his commanding officer, Lt. Arthur L. Bratcher.

The current investigation is the latest in a series of events that have cast a shadow over the Alexandria Police Department during the past three years. Strobel, who has announced that he will retire in December, was the subject of two criminal investigations that stretched over two years.

Though he was exonerated in both investigations, city officials say privately that the accusations made it difficult for him to do his job and badly damaged the department's morale. When officials began seeking a replacement for Strobel they were disappointed by the relatively small pool of applicants.

Lawson intervened to remove Strobel from the current investigation of Bratcher, city and law enforcement officials said. Strobel and Bratcher, both longtime veterans of the Alexandria Police Department, have worked closely together for years.

A major focus of the investigation is whether Bratcher failed to report allegations of wrongdoing to Strobel, a violation of department rules. Lawson has ordered the officer in charge of the probe, Deputy Chief John Streeter, to bypass Strobel and report directly to her, officials said.

Officials said that after police officers told Lawson they were being interrogated regarding news leaks to reporters, she ordered police administrators to abandon any effort to identify or punish officers who talked to reporters. Two officers, who asked not to be identified, told The Washington Post that they and others were questioned extensively to determine the source of leaks.

Mayor James P. Moran Jr. said he had been told of attempts to isolate whistle-blowers and that they would not be tolerated.

"When I saw that the police department was devoting its attention to who was leaking to the press rather than the content of the allegations, I knew we had a problem," Moran said. "We ought to have nothing to hide.

"This entire situation is very disturbing. I had really thought and hoped that these kinds of internal management problems which seem so inexplicable were over," he said. "They're obviously not."

The allegations concerning Goldberg and Bratcher stem from a drug probe being conducted by a Northern Virginia regional police task force that includes local and state officials. Streeter, the Alexandria deputy chief, was scheduled to give Lawson the results of his internal investigation last night and Lawson is expected to release a report next week.

Streeter said last week that in April, a confidential informant accused Goldberg of tipping off a friend that he was being investigated by the task force. The allegation against Goldberg was forwarded to Bratcher, who commands Alexandria's vice and narcotics unit.

Police department rules require that any allegation of misconduct by an officer be reported to Strobel. Streeter said last week that his preliminary inquiries had found that Bratcher did not inform anyone of the charge against Goldberg for about two months. The charge "was contained within the vice and narcotics division" until late June or early July, Streeter said.

Goldberg quit the police force Aug. 7 after internal investigators asked him to take a polygraph test. According to city and police officials, Goldberg was investigated for allegedly leaking information about another drug probe early this year but the allegation was never substantiated. Goldberg has not returned calls for comment.

Goldberg's lawyer has denied that he divulged confidential information and said that he resigned for personal reasons. In an internal police memo written last week Bratcher denied any wrongdoing and called the charges against him a "deliberate attempt at character assassination."

According to city and law enforcement officials, Goldberg was interviewed this week as part of the internal investigation. But they said that because he is no longer a police officer, the Northern Virginia task force will continue the effort to determine whether he leaked information.

The Alexandria internal investigation initially focused on how the allegations against Goldberg were handled, officials said, and has been broadened to look at Bratcher's management of the vice and narcotics division.

Bratcher's command is allocated 12 positions, seven of which are assigned to narcotics and five to vice. But officials say that in recent days only two officers have been working on Alexandria narcotics cases.

One of the narcotics squad's officers is assigned to the regional drug task force, one officer is new and not yet working cases, and three positions -- including two that were recently created -- are vacant, officials said. The vice squad has been functioning at full strength.

Bratcher said he has been ordered not to comment on the investigation.

Officials also said the narcotics squad has been hampered by high turnover among officers and personality clashes. According to officials, the supervisor of the narcotics squad, Sgt. Morton Ford, has frequently been at odds with Bratcher.

Ford filed a lawsuit in 1983 that contended Chief Strobel had transferred him out of detective work without justification. Two years lat- er Ford won and was reassigned to the narcotics squad.

Bratcher has supported Strobel throughout the department's years of upheaval, while Ford has publicly said that Strobel should be fired.

City Council members have cited illegal drug traffic as one of the most serious problems the city faces and have established a task force to look for solutions. City officials said that in light of these efforts, turmoil within the narcotics squad could prove particularly embarrassing.

"I cannot understand why we don't have more people assigned to narcotics and fewer people assigned to vice," said Moran. "It's a question of priorities. Our drug problem is terrible and we don't have people assigned to deal with it."