Police confirm at least four San Francisco strip clubs are under criminal investigation after more than 20 patrons filed reports against them, claiming the clubs ran up large, unauthorized charges on their credit or debit cards.

A half-dozen of those claims are detailed in a 2015 affidavit in support of a search warrant seeking club financial records obtained by NBC Bay Area’s Investigative Unit. Since then, police say at least 14 others have filed police reports claiming they were ripped off to the tune of thousands of dollars at the North Beach adult entertainment hotspots. The clubs deny the allegations, saying the claims amount to nothing more than buyer’s remorse.

The targets of the criminal probe, according to court documents, are four clubs tied to Seattle-based entertainment company Déjà Vu: Little Darlings, Garden of Eden, Roaring 20’s, and the New Century Theater. Police say they’re taking the reports seriously, urging club-goers to be cautious when frequenting these types of establishments. But some believe authorities could have trouble making any case stick in court.

“Don’t go in, just don’t go there,” said one of the alleged victims, who asked he only be identified by his first name, Steve. “It’s a very pleasing and alluring front, but you don’t know what’s going to happen to you once you go in there.”

Steve’s story begins on a night just before Christmas in 2014 as he walked to a bar in his North Beach neighborhood.

“It was late, I was lonely, you know?” Steve said. “I passed by Little Darlings. A couple of very attractive women said, ‘Hey, where you going buddy?’”

Steve said he handed over his driver’s license to be scanned by club security. An hour-and-a-half later, Steve said he expected to pay a $200 tab for a lap dance. But he says the dancer told him his debit card had been declined, so he withdrew cash from the club’s ATM to pay her.

“When I got home, I had a bad feeling,” Steve said. “I checked my balance and it was empty.”

Steve said his account was drained of $2,500. He complained to his bank, but they sided with the club in the dispute, pointing to his signature on the receipt.

“I didn’t sign a receipt,” Steve said. “An ATM receipt for $2,200 with a $300 tip? No f***ing way.”

In his police report, Steve relayed his fear that the club got his signature off his driver’s license, which had been scanned at the door.

“I handed her my card,” Steve said. “I didn’t expect skullduggery.”

But Steve is not alone. Police say they’ve heard claims detailed in more than 20 reports taken from club patrons over the past three years

“We don’t know exactly what’s going on, but we know something is definitely going,” said San Francisco police spokesman Sgt. Mike Andraychak.

The 2015 search warrant affidavit details the account of six patrons, many of whom had already been drinking before they entered the club, who claim large sums of money were charged to their bank cards without their consent.

Two told police they passed out after being served beer that they believe was drugged. One wound up in the hospital, where tests showed he had cocaine, methamphetamine and even the common ingredient in cough syrup in his system. He told police he doesn’t do those drugs and said he had arrived at the club completely sober. According to the warrant, he told investigators he never signed off on the $11,400 tab at the New Century Theater that showed up on his bank records the following day.

Perhaps the most surprising accusation detailed in the search warrant was from a man who went to the Garden of Eden in December 2014. He told police he had already been drinking when he was offered a beer at the club, and ended up passing out soon after. When he came to, he discovered that he had been charged $90,000 on what should have been a $1,600 tab. The warrant shows that just after being charged the $1,600, his card was swiped four more times in just over an hour for the following amounts: $9,550, $11,500, $23,500 and finally a whopping $45,000. The warrant does not specify what the bills were for.

Police say more than 14 other men have given similar accounts – although with less dramatic losses. The total alleged losses now top $300,000, all from the same four North Beach clubs, according to police.

Representatives of Déjà Vu declined to be interviewed for the story, but in a statement, a public relations firm says the four clubs are independently owned and that they were not aware of any investigation. They suggest the claims amount to buyer’s remorse.

“Due to our business, we go to extraordinary measures to ensure the patron is aware of the charges he is incurring; fingerprinting to videotaping each and every transaction,” the statement reads. “At no time is a dancer able to process a credit card charge without the patron present.”

The statement goes on to say that 99 percent of all billing disputes are resolved in their favor due to these procedures.

If these cases ever end up in court, Steven Clark, a former prosecutor turned defense attorney, said the embarrassing nature of the accusations gives the clubs an advantage.

“They will attack the credibility of these victims by saying you got yourself into this mess, and just because you wish you hadn’t, that doesn’t mean that our clients committed a crime.”

Clark said if prosecutions prove difficult, authorities might have more success targeting the clubs’ business licenses. In the meantime, he said patrons should exercise caution.

“I think the message here is if you want to have a lap dance, it’s buyer beware,” Clark said. “And that’s really the key here.”

As they continue investigating, police also advise customers to be aware.

“It’s like anything we say when people go out to celebrate or go out to do something,” Andraychak said. “Watch how much you drink, watch what you drink, use the buddy system.”

And for Steve, although it might be awkward, he just wants to make a stand.

“If you don’t stand up and fight back, you’re going to be robbed all the time, and I don’t want to live like that,” he said.