Defense attorney Andrew Flier said authorities illegally searched Garrett before he was arrested Feb. 1 for investigation of carrying heroin in the city subway system.
Flier says Garrett disputes the contention that he was nervous and sweating profusely, which prompted his search and arrest.
Garrett, who is free on bail, did not speak to reporters.
The 48-year-old has had a series of drug arrests since the height of his popularity in the 1970s. Flier says Garrett sought help after those arrests and accepted responsibility but plans to fight the latest case.