The twin-engine plane made an unscheduled landing at Houston Executive Airport in Brookshire about 7:15 p.m. Monday, KHOU-TV, Houston, reported.
There had been no communication with the control tower and no mayday before the landing, in which the plane appeared to have gone down on the airfield, then skidded into grass, officials said.
The plane's front nose gear was damaged or missing.
KHOU reported authorities said whoever was on the plane apparently tried to carry off bricks of marijuana but left "quite a bit" behind. The investigators didn't say how much.
Whoever was on the plane got away quickly, officials said.
"They had a few minutes head start and with cellphones these days, they could have called someone to come pick them up," said Chief Deputy John Kremmer of the Waller County Sheriff's Office.
Investigators were attempting to determine the owner of the plane, which authorities said had not been reported stolen.