A federal grand jury in Alexandria heard two new witnesses and recalled three others yesterday in its five-month investigation into allegations of misconduct in the Alexandria police department.

Assistant U.S. Attorney Justin Williams, who has called a total of 14 people before the grand jury, has declined to comment on the scope of the investigation.

Capt. John Miller of the Rockville police department, who was on the Alexandria force 15 years, appeared briefly. He declined to comment on his testimony. A woman who refused to identify herself to reporters testified more than two hours.

Alexandria police Officer Joseph Morrash and former Alexandria officers Charles Cox and Louis Pugh went before the grand jury for the second time.

Among the 14 witnesses are some who alleged that Public Safety Director Charles T. Strobel improperly cut short a 1984 city police investigation into the use of cocaine at a local restaurant. Those charges were reviewed by a special state grand jury, which last February found no basis for the allegations.

Other witnesses have been asked about allegations of illegal wiretapping and allegedly improper police conduct during the department's investigation into illegal bingo payoffs in the late 1970s, sources said.

The grand jury also has studied police records on internal investigations into wrongdoing by members of the force, a source said.