A retired NYPD sergeant working as a civilian contractor in Afghanistan was killed during an apparent “insider attack” by members of the Afghan military.

Kevin O’Rourke, 52, and an unidentified US soldier were slain Saturday in the clash with Afghan troops.

O’Rourke had been on the force for 20 years and worked as member of the NYPD’s elite Emergency Service Unit.

He was also one of the department’s scuba instructors, based at Brooklyn’s Floyd Bennett Field.

O’Rourke, originally from Long Island, retired in 2003 and later moved to Florida.

The soldier was the 2,000 service member to diein the 11-year conflict.

Three Afghan troops were also killed in the shootout at a checkpoint in the eastern part of the country.,