Disgraced Deputy Inspector James Grant was so cozy with his pals in the Orthodox Jewish community that he kept a mezuzah on his office doorpost — even though he isn’t Jewish, sources told The Post Thursday.

The symbolic gesture — affixing a traditional casing that houses a Hebrew prayer on a parchment to an entrance — was just one of the ways that Grant curried favor with prominent businessmen like Jeremy Reichberg and Jona Rechnitz, who are the focus of a federal probe into police corruption, when he was in charge of Brooklyn’s 72nd Precinct.

Both men were familiar faces in the Sunset Park station house, where Grant allowed them to park in his private spot. He also let Reichberg attend a roll call, the sources said.

At one point, Grant had his office spruced up, along with much-needed repairs to the precinct gym.

Cops assigned to the command believe that members of the Orthodox Jewish community footed the bill, even though such work is supposed to be requested through the NYPD’s Building Maintenance unit.

The NYPD didn’t respond to questions about who paid for the work.

Grant and Reichberg also had a “long-standing” friendship outside the precinct.

The two men regularly broke bread and traveled together within the US, the sources said. Reichberg also attended the first Communion for Grant’s daughter.

Grant — who told a pal, “I’m ­f–ked,’ when he learned of the probe — was caught accepting gifts of diamonds and cash from Reichberg, sources have said, and was placed on modified duty Thursday.

“He’s a good family man,” insisted Grant’s lawyer, John Meringolo. “He’s a great police officer and a great father.”