The use by Alexandria police of undercover agents who engaged in sexual acts as part of a probe of message parlors violated no law and therefore a grand jury will not be asked to investigate the practice, according to the city's acting prosecutor.

Frederick Ford, an attorney representing several massage parlors, charged at a City Council hearing last month that the commonwealth's attorney's office had "covered up" police misconduct and, in doing so, had paved the way for future law violations by police.

Acting Commonwealth's Attorney John E. Kloch asserted in a letter to Ford on Jan. 2 that the actions of under-cover agents "constitute nothing more nor less than police investigation of suspected illegal activity."

Ford said in response that Kloch's letter "makes it abundantly clear that in his view so long as police are conducting an "investigation of "suspected illegal activity,' they can commit any illegal act they want and get away with it."

Alexandria police have been criticized for using civilian volunteers in investigations of both massage parlors and drug trafficking. These investigations resulted in strained relations between police and the prosecutor's office when cases were either dismissed on grounds of governmental misconduct or dropped by the prosecution.