New York City police officers were warned against using their personal cell phones to record video or take pictures while on duty unless authorized by a supervisor, the New York Daily News is reporting.

"Members of the service are reminded that any video or audio created by any device, including a personal device becomes a record for legal purposes and is therefore subject to applicable evidentiary laws," NYPD administrators said in an order dated Aug. 7 which prohibits cops from taking photos or video and audio recordings "during any encounter."

The memo was sent out a day after rank-and-file cops were reminded that they can't legally take action to stop someone from filming them while they're on the beat.

No particular court case prompted the warning and the "no record" rule has been on the books for some time, according to an NYPD spokeswoman.

"We frequently issue internal memos to members of the service reminding them of the department's policy and procedures," the spokeswoman said.