Investigators were on a top floor of NYPD headquarters last week searching for evidence in the tawdry sex-for-overtime abuse scandal exposed by The Post, sources said.

NYPD Lieutenant Quathisha Epps has accused Chief Jeffrey Maddrey of sexual exploitation, alleging he used his power to coerce her into unwanted acts in exchange for overtime.

More female officers in disgraced top cop Jeffrey Maddrey’s orbit pulled down massive overtime and other perks, The Post has learned.

Maddrey’s denials did nothing to halt the ongoing shake-ups in the NYPD, particularly in the Internal Affairs Bureau, which would have been responsible for investigating him for sex abuse