An apparent stowaway who suffocated to death was found on Friday in the main wheel well of an American Airlines passenger jet when it landed in Detroit from Miami, authorities said.

"He was a thin black male in his early 20s," said Detroit Metropolitan Airport spokeswoman Barbara Hogan.

She said a ramp worker found the apparent stowaway at about 1 a.m. EDT, minutes after the Boeing 737 ended its three-hour flight from Miami.

The Wayne County Medical Examiner's Office later determined he died from a lack of oxygen or "high altitude hypoxia," Hogan said.

She added that authorities were still trying to identify the man late Friday afternoon.

Martha Pantin, a spokeswoman for American Airlines, said she was unable to comment on reports the flight to Detroit originated in the Dominican Republic with a stopover in Miami.

"Our planes go all over the place but we're not going beyond that," she said.

(Reuters)