Officer Pedro Serrano, 43 years old, said after he contacted the NYPD's InternalAffairsBureau to complain, stickers of "rodents" appeared on his locker.
"As it would with any such allegation, regardless of its credibility, IAB is investigating it, " said the NYPD's chief spokesman, Paul Browne, referring to the internalaffairsbureau.
Bloomberg's office referred calls Tuesday to the NYPD, which said it already gets plenty of oversight from its 700-person InternalAffairsBureau, a civilian complaint board, a police corruption commission, prosecutors, judges and a 1985 federal court settlement that set guidelines for its intelligence-gathering.