The NYPD destroyed an officer’s memo books that detailed the department’s alleged enforcement of racist quotas and the retaliation he faced for whistleblowing, a Manhattan federal judge said in newly revealed court papers.

Officer Pedro Serrano was forced to hand over six of his memo books to an “integrity control officer” in 2013 after he filed a complaint with the Equal Employment Opportunity Commission, claiming he faced retaliation and racial discrimination in the Bronx’s 40th Precinct.

Serrano and other officers later sued the city over the alleged bias, and he had asked that one of the books be handed over as evidence in his case, according to court records.

The city failed to produce the document, however. All they ever gave Serrano’s legal team were photos of a few of the notebook’s pages, some of which were blank.

Judge Sarah Cave wrote in an opinion filed Thursday that Serrano is entitled to an “adverse inference” related to the book. That means he can argue in the case that “there is a likelihood that the destroyed Memo Book would have supported [his] claims of adverse employment action and retaliation.”

Serrano joined a number of other officers who are suing the city, claiming they faced racial discrimination and were ordered to enforce racist quotas in precincts across the city.

Serrano had in 2019 requested that the NYPD produce one of his memo books for evidence, since inside he had written down “each time [he] was retaliated against and in what ways,” court papers state. He also made note of “punishments he received for not making the quota.”

The city argued they had preserved the memo book through photographs, but only produced images of five pages, two of which were blank. Another photographed page had only three lines of information, according to court papers.

“We take our discovery obligations seriously. We believe the photos of the key pages in the memo book the NYPD provided were sufficient, and we are reviewing our options.” Nick Paolucci of the NYC law department said in a statement.

Serrano’s lawyer said the judge’s opinion will hopefully stop the department from destroying evidence in the future.

“The city flaunted the ethical rules that our system is based on in purposefully destroying Pedro Serrano’s memo books. The court’s ruling confirms this fact and will hopefully go a long way to prevent the NYPD from destroying damaging evidence in the future,” lawyer John Scola, told The Post.

Separately, Cave ruled in the same opinion that former Police Commissioners James O’Neill and Bill Bratton will not have to be deposed in the case.

Another officer in the suit had claimed both Bratton and O’Neill came to the 40th Precinct after a media report about officers there downgrading felonies in an effort to make crime appear lower in the precinct.

Bratton allegedly singled out officer Sandy Gonzalez at the precinct’s roll call, saying “a disgruntled officer among them had dropped the dime on the entire precinct.”

O’Neill also asked the officers at the roll call if anyone was recording the meeting.

Cave ruled there was not sufficient evidence to suggest Bratton and O’Neill were singling out Gonazalez for retaliation because they did not mention him by name — and therefore do not need to be deposed.

Additional reporting by Olivia Bensimon