District Attorney George Gascon said the latest 42 cases being let go bring the total so far to 57, the San Francisco Chronicle reported.
The newspaper said the scandal involving eight plainclothes officers who allegedly made warrantless searches and failed to properly identify themselves while conducting raids at residential hotel apartments has led to separate investigations by the FBI, the district attorney and the city police.
The officers in question, who also allegedly lied on police reports detailing the searches, have been assigned to administrative duties, the Chronicle said.
Gascon was police chief at the time the searches were made late last year and early this year.
Eight of the dropped cases involve allegations of theft based on one or more undercover officers posing as vulnerable people in a crime-plagued area, the newspaper said.