A 25-year-old United Airlines passenger said she was forced to sit next to a man who pleasured himself while staring at her during an early morning flight ahead of Labor Day weekend.

The passenger said she was also surprised to learn that, despite reporting the incident to flight staff, the airline did not inform law enforcement, and the man deplaned at Newark Liberty International Airport in Newark, New Jersey, as if nothing had happened.

The woman, whose name NBC News is withholding because she is a victim of an alleged sexual offense, said she was permitted to stand for part of the roughly one-hour regional flight from Rochester, New York, to Newark that took off at 6 a.m. Sept. 3.

A pediatric crisis therapist who lives in western New York, she said it was the first leg of her trip to visit friends for the weekend in Boston. When flight attendants began to prepare for landing, the woman told NBC News, she was told she had to return to her seat in spite of the sexual harassment she reported, because there were no other available seats.

“On multiple instances, I said I feel uncomfortable doing that,” the woman said.

She said a flight attendant told her she would only be sitting for three to five minutes, but the landing process took much longer, and her seat was near the back of the plane, so she spent additional time alongside the man before deplaning.

The woman described the man as roughly 35 to 40 years of age, wearing hiking pants and a T-shirt. He was “pretty normal looking” and “unassuming,” she said.

“I just got the sense had done it before ... People don’t just do those things at 6 a.m.,” she said. The airline’s handling of the issue made the upsetting encounter worse, she added.

According to the passenger, she approached a United agent at the gate who was rude and curt. The woman told the agent that her seatmate was not stopped at the gate and that she was “concerned he’s on his next flight.”

“What am I supposed to do about it?” the agent allegedly told her. He said it was her responsibility to request a police response, she said.

Another United employee later told her that protocols weren’t followed and advised her to complain to the airline. She said she filed grievances with United Airlines and the Federal Aviation Administration. Later, she said, she also called the FBI.

In an emailed response to NBC News’ request for comment, United did not immediately provide details about the report or how it was handled. “We’re currently looking into this and don’t have anything additional to share right now,” a spokesperson said.

The FAA and the FBI also declined to comment.