Police are investigating the discovery of a dead fetus aboard a Continental flight, which landed in Houston on Sunday.

A cleaning crew who found the fetus about an hour after Continental Airlines Flight 433 from LaGuardia Airport, New York landed at Bush Intercontinental Airport, Houston informed authorities. The plane landed at gate 18 at 4:45 p.m., about 30 minutes behind schedule, the Houston Chronicle reported. The gate was located at the far end of the airport building.

The fetus was found in a trash bag in one of the plane’s rest rooms after passengers already had disembarked. Investigators could not tell how far along the fetus might have been in its development.

Homicides detectives are trying to determine if the fetus was left in the restroom in mid-flight or while it was on the ground.

Medical examiners will perform an autopsy on the fetus and determine the cause of death.

The investigation is expected to be handled by the Federal Bureau of Investigation if proved it was a crime.

“If a crime was committed on the aircraft, then it would make it the FBI’s jurisdiction,” FBI representative Shauna Dunlap said.

The Houston Police Department is also investigating the case.

No further information was immediately made public.