A Port Authority employee made the grisly discovery of a man’s corpse floating in the waters off a Brooklyn pier Saturday evening, authorities said.

The unidentified body, believed to be a man of 50 to 60 years old, was spotted by the employee at the Red Hook Container Terminal at around 5 p.m. between piers 9 and 10, according to a Port Authority spokesman.

The NYPD Harbor Unit removed the body and the medical examiner will determine the cause of death, cops said.