A Chicago Merrill Lynch banker allegedly drugged and sexually assaulted a woman, leaving her with an STD while she was on vacation in Capri, Italy, with two friends last year, according to a lawsuit filed Wednesday.

Sahra Isla — a French-born marketing and communications manager — alleges in a new Cook County, Illinois, lawsuit that while she and two girlfriends were on vacation, she was sexually assaulted by Thomas Kane, a private wealth manager, on July 1, 2018.

The three women met up with Kane — an acquaintance of Isla’s friend from New York — after a lodging debacle that left them without a place to stay in high tourist season.

Kane — who had been on vacation with his parents in Puglia — let the women stay in his hotel suite for two nights, the court papers say.

On his last night, the 34-year-old woman — who also has an apartment in New York — says they all went to a club, where Kane ordered table service and poured Isla a gin and tonic.

After the first drink, Isla began “feeling somewhat disoriented,” the court documents say.

But Kane pushed a second drink on Isla, despite her protests, and after finishing just half of it, “she began to feel extremely dizzy and tired. A wave of exhaustion hit Plaintiff and she could no longer stand,” the lawsuit says.

“Plaintiff had never felt this way before, and she tried to lay down on a bench next to the table.”

Isla says she started blacking out and has flashes of memory of Kane carrying her on his back in the rain to the hotel, according to the court papers.

Surveillance from the hotel shows Isla on Kane’s back — and eventually on her feet but barely able to walk as she leans on him, the court documents say.

The next day, Isla woke up naked in Kane’s hotel room bed, rather than on the pull-out bed she had slept on the night prior. She felt pain in her genitals and later found out from a doctor that she had contracted chlamydia from him, according to the suit.

“Defendant drugged Plaintiff and engaged in non-consensual sexual acts before leaving Capri for the United States,” the lawsuit charges.

“I think he planned everything in advance because he knew he was leaving and by the time I would wake up, it would be too late to call the police,” Isla told The Post.

“I wake up on my stomach and I have a massive headache. I don’t know where I am and I’m completely naked.

“I see my clothes on the floor. My dress was ripped … I feel that there is something wrong and then I realized what happened,” Isla recounted.

In a September text message, Kane told Isla’s friend, “I know you knew how much I really liked Sahra and wish you knew that I could never do anything without her consent and active participation,” the suit says.

Isla filed a police report the day after the alleged incident with Sardinian police. Her lawyer, Eddie Hayes, explained that the investigation never went anywhere since Kane lives abroad.

“Kane says she consented but how could she have when she couldn’t even walk?” Hayes said.

“I absolutely don’t care about the financial side of it. I just want him to be punished and not to do this ever again,” Isla said, adding that she hasn’t been the same since the alleged incident.

“I was completely dead inside for the past year. I still haven’t recovered. I am trying to live a normal life. I try to socialize. I can’t date. It’s so, so difficult for me,” she said.

Kane’s lawyer Andrew Schapiro said, “This is nothing more than a shakedown. Ms. Isla’s lawyers have been asking us for a payment for weeks, but we refused.

“We have documentary and photographic evidence establishing the consensual nature of the parties’ relationship, and the facts will tell the true story soon enough,” Kane’s lawyer added.

“There is a lot more to the relationship between these two individuals than Ms. Isla and her lawyers are telling you,” Schapiro said.

Schapiro responded to the videos that appear to show Isla stumbling and being carried on Kane’s back: “Suffice it to say that the videos do not reflect either what happened next, in private, or what had previously occurred between the two.”