Bernard Shore, a critical-care EMT who offered an undercover Post reporter $400 to take his state certification exam, is no longer on the job — and is under investigation by Nassau County prosecutors.

Shore, 64, a member of the volunteer Port Washington, LI, Fire Department, advertised on Craigslist for a paramedic to take the exam for him, claiming he couldn’t sit for the test because of a bad back.

He produced a phony department ID card in his name, but with the reporter’s photo.

“Mr. Shore has been relieved of his duties until further notice,” said Robert Kropacek, chairman of the department board of directors.

“We are aware of and stunned by the New York Post article. We are fully cooperating with any law-enforcement or administrative investigations. We are cooperating with the Nassau County District Attorney’s Office.”

Shore planned to dupe the state Department of Health, which administers the certification exams that EMTs must take every three years to remain licensed.

Shore told a retired New York paramedic working with The Post that he piloted the department’s fire-rescue boat.

In a rendezvous with the undercover reporter, he handed over the fake ID, $100 up front — with $300 to be paid after the exam — plus a $20 money order for the exam fee, an admittance card to the exam at La Guardia Community College, in Long Island City, Queens, and two No. 2 pencils.