A Louisiana police department has issued an apology for the “offensive” behavior of its officers — over 25 years after they wore blackface to go undercover during a narcotics operation.

The mea culpa from the Baton Rouge Police Department came Monday after a photo circulated showing two male officers in blackface and sunglasses, and one of them throwing up gang signs.

The photograph, which appeared in the Baton Rouge Police Department’s 1993 yearbook, identified the cops as “Soul brothers.”

“Blackface photographs are inappropriate and offensive,” Police Chief Murphy Paul said in a statement. “They were inappropriate then and are inappropriate today. The Baton Rouge Police Department would like to apologize to our citizens and to anyone who may have been offended by the photographs.”

The racist photo was first reported by The Rouge Collection, a local publication.

The cops in the photo were identified as Crimestoppers coordinator Lt. Don Stone and police Capt. Frankie Caruso, who is now retired, according to the Advocate.

The duo dressed in blackface as part of a department-approved drug sting, Paul confirmed. The department’s two black narcotics officers were too well-known in the area at the time.

“Not only do they not know we’re cops — they don’t even know we’re white!” then-Detective Caruso told the Advocate newspaper in 1993, according to the Washington Post.

Caruso and Greg Phares, the police chief at the time, said the officers dressing in blackface was not intended to degrade black people — but meant to help clean up the streets.

“You got to dress the part,” Caruso recently told the Advocate. “It wasn’t done offensively.”

Paul said the department is unable to “apply existing policies to conduct that happened before the policies were in place” while noting that the incident wouldn’t be tolerated in the present day.

“Today, we would not allow our officers to wear blackface in an official capacity under any circumstances,” he said. “We have policies in place to prevent our officers from engaging in this type of behavior both on and off duty.”