The Alexandria City Council last night approved a measure that will allow police to engage in sexual activities while investigating massage parlors.

The amendment to the city code, approved unanimously, exempts local, state and federal law enforcement officials from penalties prescribed under city laws designed to curb sexual activities at massage parlors.

The measure essentially frees police to begin undercover investigations of Alexandria massage parlors.

The city has tried for years to rid itself of sexually oriented massage parlors. While federal prosecutors secured the conviction last year of Louis Michael Parrish for operating a major Alexandria-based prostitution ring involving massage parlors and outcall dating services, the city's own efforts have been consistently frustrated.

Last year, an Alexandria judge threw out of court requests by the city attorney for injunctions against two massage parlors, saying they must first be convicted of a crime.

That ruling followed by one year the dismissal of several massage parlor cases on the grounds that police acted illegally by participating in sexual acts during their investigations.

City Manager Douglas Harman said the ordinance is the work of former U.S. prosecutor Brian P. Gettings, whom the city hired in April to suggest ways of regulating massage parlor activities.

Gettings is being paid $7,000 to review the city's past attempts at cracking down on massage parlors.