Flight 202 departed from Chicago's O'Hare airport on Tuesday morning and landed at Maui's Kahului airport.
After landing, United Airlines said a body was found in the wheel well of one of the main landing gears on an aircraft.
"United is working with law enforcement authorities on the investigation," the company said in a statement to ABC.
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The aircraft was a Boeing 787-10.
The wheel well was only accessible from outside of the aircraft, United Airlines said.
At this time, it is not clear how or when the person accessed the wheel well.
The Maui Police Department said they were investigating.