A Manhattan landlord is on the hook for $250,000 in city fines for turning his five-floor walk-up into an illegal hotel — so he’s suing a tenant who he says repeatedly flouted building rules by renting her apartment to Airbnb travelers.

“We were unaware of the rental scheme,” said Lawrence Silberman, attorney for the owner of 357 W. 54th St. “We did not participate or profit from it. But this is now a policy of the city. The tenant does not get named or fined. The landlord’s strictly liable.”

Silberman says his client has been playing a “cat and mouse game” with tenant Madaline Iacob, who allegedly claims the Airbnb guests were actually friends and family.

City inspectors issued violations to the building owner in May after finding Iacob was charging $200 a night for a stay in her $2,000-a-month, one-bedroom apartment.

When a second inspector caught Iacob in July and issued more $1,000-a-day penalties, she told the landlord the guests were “friends and relatives,” according to Silberman.

But the inspector’s report identifies the people staying in Iacob’s first-floor unit as a family of five from Colorado who had rented the pad from “Ramona” on Airbnb.

Silberman said his client has had trouble catching Iacob because the walk-up building doesn’t have a doorman.

A city administrative-law judge in November found Iacob “was indeed involved in a short-term-rental scheme and as a result the court imposed a substantial penalty based on chronic bad acts,” the suit says.

A city judge slapped the Midtown landlord with a $61,250 fine. The building owner expects to pay quadruple that for another eight violations related to Iacob’s Airbnb hosting throughout the summer.

Iacob told The Post she is not an Airbnb host and claimed she wasn’t aware of the lawsuit, which asks for $250,000 to cover the fines plus another $50,000 in legal fees.