They’re swinging free!

A wild swingers club has been operating out of a Financial District office building — with wall-shaking sex parties throughout the workday — and the cops say there is nothing they can do about it, sources told The Post.

The Amsterdam Club, which promises on its website steamy parties in a space that is part Playboy Mansion and part lounge, has been a huge distraction for the building’s other tenants — including tech companies and a financial research business.

“You see these people coming up. The bouncer looks like he’s from a strip club,” said one disgusted worker at 27 Cliff St.

“This is an office building. We saw them move eight mattresses up there! That was horrendous.”

A task force including NYPD cops raided the place on Sept. 19 — but all they could do is give the tenants a summons for selling liquor without a license.

As long as the participants are just swapping sex for free, there’s nothing cops can do about it, sources said.

“We’re furious,” said another neighbor concerned about “the kind of people that are in there.”

“We come in the morning, and you can smell cigarette smoke in the halls. We found drugs in the lobby. There’s condoms in the trash in the back. It’s horrifying.

“We’re worried about our reputation as a business. We want it out of here.”

Another neighbor said he understands it’s not illegal but thinks they should at least keep the moaning and groaning quieter.

“If they can go that long, God bless them, but we shouldn’t have to hear it,” one tenant complained.

The building’s landlord told The Post that the founders of the Amsterdam Club claimed they were a video production company when they signed the lease.

He has filed a lawsuit to get them evicted.

“The lawyers are working on it,” he said.

The head of a company that rents space at the building said he has heard the partying while meeting with clients.

“It’s infuriating and embarrassing for me, because I have our team and our employees in these conditions,” he said. “It’s horrible in every sense. We’ve had meetings and we’ve heard things.”

Another worker added, “You can hear them singing. You can sometimes hear sounds that are not sounds you want to be hearing in the office.

“They often will do sexy karaoke, so you can hear that quite clearly through the wall.”