The deputy chief of Alexandria's embattled police force was relieved of command over criminal investigations yesterday and placed in an administion position in what one high-ranking officer called "a major shake-up" of the department.

Deputy Chief Clyde Scott, 39, the officer who initiated the controversial massage parlor investigation using a civilian volunteer and an undercover policeman, was replaced by Inspector Arlen Justice, also 39.

Scott, who was not available for comment, will retain his title as deputy chief in his new position as head of the force's administrative services bureau, a division known as the department's "paperwork" unit.

Justice, who will become the force's second deputy chief, said yesterday, "There are going to be some changes made" in police operations in the city. He said his "first priority" will be to "dispel" any "implications" that the Alexandria force is ineffective.

In his new position, Justice will coordinate the activities of the city's criminal investigators, its uniformed patrol and special operations divisions.

Police Chief Charles T. Stobel, who directed the changes, said yesterday that the shift in command was not a result of Scott's handling of the massage parlor investigation which has been called a "failure" by city officials.

Scott, a 20-year veteran of the Alexandria force, testified in court Aug. 31 that he initiated the investigation last March and authorized a civilian volunteer and an unmarried policemen to solicit illegal sexual acts from masseuses.

That activity was ruled governmental misconduct by a judge who said he could not decide who was the "bigger whore"-the masseuse of the civilian volunteer.

Strobel said yesterday that the 332 member police department which he has commanded more than a year, has been subjected to "unfair publicity" in recent months.

The City Council, troubled by reports of poor morale and sloppy police work, announced last week that it would look into the department's problems in a closed session Jan. 9, followed by a public session.

"We may not have made all the right decisions," said Strobel yesterday, "but we haven't made all wrong ones either. I'm a yound administrator. I've got things to learn."

In addition to the massage parlor probe, police handling of an undercover narcotics investigation that used two women to solicit drugs form mem in "singles" bars was sharply criticized by the commonwelath's attorney's office.Prosecutors said they were forced to drop the more than 26 criminal cases that the women had developed.

Several week ago, Joseph Soos, an investigator who worked on the as-yet unsolved murder case of socialite Donita Cutts, quit the force in disgust. He later said police handling of a suspect in the Cutts case was "the final straw," in what he termed the department's "failure to live up to the high standards" needed in law enforcement.

Strobel, in announcing the changes yesterday, said it was part of his over all reorganization "done to improve the department's efficiency any productivity . . . giving more attention to internal management."

The police department has been criticized for its lack of communication, not only with the commonwealth's attorney's office, but within the force.