Two NYPD detectives had been working security for the cryptocurrency investors who police say kidnapped a man and held him captive in SoHo, police sources say.

One off-duty detective drove the alleged victim from the airport to the SoHo townhouse on May 6, sources told ABC News.

At least one NYPD officer has been placed on modified duty as part of an internal investigation into the kidnapping and torture of a man in SoHo, the department confirmed Thursday. A police spokesperson said "members of the service were modified" on Wednesday, but declined to elaborate, saying only that the matter “is under internal review.”