The city allegedly ignored a probe which uncovered sexual misconduct and other problems in its lifeguard program — then canned an investigator who called out the lack of action, he claimed in a lawsuit.

Danny Dalton, an assistant inspector general with the city’s Department of Investigation, said he was sacked after pushing for DOI to do something with its own findings.

“They knew there was a huge problem and they just kept kicking the can down the road,” Dalton, 66, told The Post this week from his home in Maine. “New York City itself is a very political place. A Big Apple cart, but it’s all pretty rotten,” he said.

Dalton, a former US Drug Enforcement Administration agent, joined DOI in 2019 amid an ongoing probe of the lifeguard program.

The investigation revealed “sexual misconduct, negligence and a lack of accountability within the program, posing a significant risk to public safety,” according to his Manhattan Federal Court lawsuit.

But once the investigation wrapped nothing was done, even after media coverage of the program, including a June 2020 profile in New York magazine describing lifeguard supervisors union head Peter Stein as a control freak who enjoys ­“f–king with people’s lives,” the DOI found.

Dalton complained to the city’s Public Advocate and City Council in May 2021, he said in court papers.

By August 2021, “DOI fired him with no explanation,” he alleged in the litigation.

Dalton, who is seeking unspecified damages, now works at DoorDash to make ends meet and set up a GoFundMe to help pay his legal bills.