SAN FRANCISCO—Authorities are investigating at least four San Francisco strip clubs after more than 20 patrons accused the establishments of running their credit and debit cards with unauthorized charges.

An NBC Bay Area investigation discovered four gentlemen’s club associated with the Seattle-based company Déjà Vu — Little Darlings, Garden of Eden, Roaring 20’s and the New Century Theater — have been accused of credit card fraud.

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

A 2015 affidavit obtained by an NBC Bay Area investigation discovered six patrons who claimed large sums of money were charged to their bank cards without consent.

One unidentified patron claimed his bank card was charged a total of $90,000 on a $1,600 tab after he passed out at the Garden of Eden in December 2014. His bank card was allegedly swiped four times in one hour for $9,550, $11,500, $23,500 and $45,000, according to the 2015 affidavit.

Two patrons believe they were drugged when they were served beer. One was hospitalized and tests confirmed the presents of cocaine, methamphetamine, and ingredients from cough syrup in his system. He told police he did not take those drugs, and was unsure how they entered his system.

The same patron said his bank card was charged $11,400 for a tab he never signed for at the New Century Theater, according to the affidavit.

At least 14 other patrons have filed similar reports since authorities obtain the gentlemen’s club financial records, authorities indicated.

A sum of $300,000 has been allegedly stolen from club patrons from the four North Beach clubs. Déjà Vu denies all allegations.

“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 . At no time is a dancer able to process a credit card charge without the patron present, ” Déjà Vu said in a statement to NBC Bay Area investigation.