This is the shocking moment a forklift extension crashed down onto the back of a pickup truck narrowly missing a worker at a Thai warehouse.

CCTV footage shows the forklift carefully lowering a heavy car part onto a waiting pickup truck, with a worker guiding the operation from behind.

However, the metal extension arm suddenly broke loose and slammed down onto the truck's bed just inches from the worker's head.

No one was injured in the incident at the spare parts depot in Samut Prakan, just outside Bangkok, on November 3.

An investigation revealed that the accident was caused by a stuck bearing in the forklift mechanism.

Unaware of the jam, the operator reportedly kept pressing the control button, increasing tension in the chain until it gave way.