An NYPD detective was suspended this week after being questioned by the FBI as part of an investigation into his conduct, The Post has learned.

Det. Saul Delacruz, a  Field Intelligence Officer assigned to the 100 Precinct in Queens, is being probed by the feds in connection to possible criminal activity, the details of which were not immediately known, according to police sources.

Delacruz, who joined the force in 2014, was suspended without pay Tuesday, the NYPD confirmed.

“There is zero tolerance in the NYPD for corruption or criminal activity of any kind by any member of the service,” a police spokesman said Wednesday. “The investigation is active and ongoing at this time.”

The 30-year-old detective was involved in an off-duty shooting in Queens earlier this month. He told fellow cops that he approached a “suspicious” man he believed was armed, and that he returned fire after the man shot at him.

It’s not clear if the federal probe is connected to that Nov. 8 shooting.

The FBI and federal prosecutors did not return requests for comment.

Delacruz could not immediately be reached Wednesday.

“He’s in a lot of trouble,” a source who was briefed on the matter told The Post.