The co-creators of the "Bumfights" video series were arrested in Thailand over the weekend for allegedly packaging child body parts stolen from a hospital, and shipping them to the U.S. ... labeled as "toys."
According to multiple reports ... Ryan MacPherson and Daniel Tanner were busted when a scan of the boxes by a Bangkok parcel company revealed the gruesome discovery.
The 3 boxes -- reportedly intended for friends in Las Vegas as a prank -- contained several body parts ... including a child's foot, an infant's head, an adult heart and 2 pieces of adult skin.
Both guys were taken into custody and questioned by cops, but were eventually released for lack of evidence. They've since fled to Cambodia.
MacPherson and Tanner made millions in the early 2000s off their "Bumfights" videos ... which pitted homeless people against each other.