(CNN) - Investigators arrested a man they say unbuttoned the shirt and pants of a sleeping female passenger and put his hand down her pants during a flight, according to a criminal complaint filed in federal court.
Prabhu Ramamoorthy faces a charge of aggravated sexual abuse after a 22-year-old woman accused him of assaulting her on a Spirit Airlines flight from Las Vegas to Detroit on Wednesday morning.
The case is just one alleged example of what some women have said is a hidden reality of commercial air travel. Though it's difficult to track how frequently assaults occur on flights, FBI investigations into midair sexual assaults have increased by 66% from fiscal year 2014 to 2017.
The federal public defender's office declined to comment on the Ramamoorthy case. Richard O'Neill, Ramamoorthy's appointed attorney, did not immediately respond to CNN's request for comment.
A detention hearing was held Thursday. According to the Detroit News, O'Neill said, "I have a hard time with some of these allegations but that's what a trial is for. There have been no allegations from anywhere that his behavior has ever been inappropriate prior to this incident."
The woman said she fell asleep leaning against the window, the complaint states. She woke up to a hand down her pants and noticed that her pants and her shirt were unbuttoned and the passenger next to her was fondling her, according to the complaint.
The passenger stopped when she woke up, and she immediately reported the incident to a flight attendant, the complaint states. Two flight attendants told investigators that the woman was visibly upset and was crying, the complaint states.
Ramamoorthy was taken into custody when the flight landed. He said in a written statement that he was in "deep sleep," the complaint states. He also said that the woman fell asleep on his knees and he is "not sure where [he] kept the hand on her."
"Through my knowledge I didn't [sic] anything to her," Ramamoorthy said, according to the complaint.
He gave a further statement in an interview with an FBI agent, saying that he "might have" undone the woman's bra while playing with it, and that he had cupped her breasts over her clothes, the complaint states. He indicated that he unzipped her pants part way and put his finger into her pants and tried to fondle her, the complaint states.
Ramamoorthy was ordered detained pending trial, based on the evidence against him and because he has significant family or ties outside the US, according to court documents.
Spirit Airlines said it is fully cooperating with law enforcement and referred questions to them.
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