The NYPD is probing an incident last week involving an Orthodox jaywalker and a Brooklyn street cop he claims made him violate Shabbat.

If the allegation that the cop threatened to lock up Rabbi Shalom Emert unless he wrote down his name is true, the officer did not follow his training and showed unprofessional conduct, says an expert on police procedure.

Eli Silverman, professor emeritus at John Jay College of Criminal Justice and author of “NYPD Battles Crime,” says cops are trained to be sensitive to religious beliefs and practices and defer to them whenever reasonable.

“This was clearly an unprofessional choice of behavior on the part of the police officer,” said Silverman. “If the story is as it was portrayed in the newspaper account, the actions violate the very motto of the police department — courtesy, professionalism and respect.”

Rabbi Emert, 27, told the New York Post this weekend that he was crossing Kings Highway at East 15th Street in Midwood around 5:40 p.m. Friday — about 90 minutes into the Shabbat — when two cops approached in the middle of the street and ordered him to produce identification. When the rabbi said he didn’t have his wallet but offered to be escorted home to produce ID, one officer demanded that he write down his name legibly or be faced with arrest, he said.

Fearful of incarceration, the rabbi complied. “I had no choice,” he told the Post.

Efforts to reach Rabbi Emert at his home and via cell phone on Tuesday were unsuccessful. He was to appear on a Jewish radio program Monday night, “Talkline with Zev Brenner,” but canceled at the last minute, Brenner said Tuesday.

Paul Browne, the NYPD’s Deputy Commissioner for Public Information, said in an e-mail Tuesday, “The matter is under review as a result of [Rabbi Emert’s] assertions.”

Councilman David Greenfield, who is Orthodox and represents part of Midwood, called for the suspension of the two officers involved and a full investigation.

“Are there no major crimes occurring in this city that these two officers can spend their evenings ticketing jaywalkers in residential neighborhoods?” said Greenfield in a statement. “Why couldn’t these officers simply have escorted this religious person to his home? There was no reason to force this observant Jew to transgress the Sabbath by forcing him to write when the officers knew that they were going to write down his information anyway to hand him a summons.”

Silverman, a longtime professor of law, police science and criminal justice administration, said while officers are free to collect information in different ways during street stops, the allegations in this case suggest the officer went too far.

“Discretion is an important ingredient in policing, but this seems like an inappropriate use of that discretion,” he said.

While such incidents may lead the public to call for better sensitivity training for officers, Silverman said current training is sufficient.

“Generally speaking they are giving cultural sensitivity training to be aware and conscious of the practices and beliefs of residents of the community,” he said. “This is clearly a violation of their training.”

Silverman said that given the media attention he considers it likely that the officer will face some kind of discipline, such as a transfer to another precinct, to prevent similar incidents by other officers.

“There are all kinds of Siberian types of transfer when you want to make someone suffer,” said Silverman. “If they live in Staten Island you can send them way up to the Bronx. It’s what message you are sending, that’s the important thing.

“My instinct tells me they will take this seriously, but I could be wrong.”