The decomposed body of a foetus fell off the back of a pickup onto the Bangkok-Chon Buri motorway shortly after the vehicle merged into traffic on Tuesday morning.
Prawet Police Station was alerted of the incident at 11am. Officials had to close one traffic lane to retrieve the body.
A doctor on the scene said the male foetus had been about eight months in gestation when the pregnancy was terminated two or three days ago, according to the stage of decomposition.
Witnesses told police they had seen a black bag bounce out of the back of a pickup truck and it was hit by another car, causing the towel-wrapped body to emerge.
Police are checking CCTV footage to try to locate the pickup. The body was sent to the Police Hospital for an autopsy.
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