The horrific scene unfolded on the side of a main round in the east of the country last night, after a workman noticed a putrid liquid leaking from the parked vehicle.
It is now believed that the victims were trapped in the trailer, suffocating inside before being discovered days later.
According to Lindsey Hilsum, a Channel 4 reporter who was at the scene, there was a ‘terrible smell of death’ coming from the vehicle.
And Austrian newspaper Krone has confirmed that three people have been arrested in connection with the truck, after a huge manhunt was launched.
Austria’s Interior Minister spoke of a ‘dark day’ for the country after the discovery, adding that the government would take a zero tolerance approach to people trafficking.
The 7.5 tonne vehicle has been towed away form the scene for the bodies to be removed, and is being examined by forensics teams.
It is registered to a Romanian citizen at present.