A longtime chief city lifeguard might need some rescuing himself after the Department of Investigation revealed Monday that he refused to be questioned about “systemic problems” plaguing the program to keep Big Apple swimmers safe.

The DOI launched a 16-month probe after a profile in New York magazine last year described Peter Stein — whose job as the head of the lifeguard supervisors union, Local 508, keeps him from actually having to save any lives — as a control freak who enjoys ­“f–king with people’s lives.”

Stein and Richard Sher, who also holds the title of chief lifeguard, were both contacted “multiple times to arrange their interviews and offer them an opportunity to provide their perspectives,” the DOI said.

“However, both ultimately did not respond to DOI to schedule interviews,” according to the 18-page report.

The DOI also noted that Sher failed to issue any findings after holding a 2014 hearing on a lifeguard supervisor who was accused of licking his finger and touching it to a workers face.

The case was eventually dropped and the unidentified supervisor still has his job, according to the DOI.

Stein, 76, raked in $179,667 in fiscal 2021, according to city payroll data posted on the SeeThroughNY Web site, and another $53,003 from DC 37 municipal union in 2020, according to the latest figures posted online by the US Department of Labor.

Sher, 81, recently retired, according to the report. He reportedly took home $75,561 in fiscal 2021.

Monday’s report said the botched handling of the saliva-smearing supervisor was part of the “systemic problems with the management and accountability of the Lifeguard Division that are attributable, in large part, to an entrenched structure and culture.”

Neither Stein nor Sher returned messages seeking comment.

But in a statement, DC 37 said, “Our lifeguards perform heroically year-after-year. Over the last eight years, there have been zero drownings where a lifeguard is on duty.”