Police went to investigate reports of a woman being assaulted in a car, only to find two "zombies".
Officers rushed to junction 11 of the M62 near Manchester after receiving a call that a woman was being attacked by a man.
But when they arrived it turned out to be two actors in full zombie costume, including fake blood, on their way to work as extras.
Greater Manchester Police said the panicked caller phoned 999 at 5.45pm on September 25 reporting an assault near the the junction at Birchwood and Warrington, but when officers realised what had happened they took no further action.
A spokesman said: "The officers probably got a bit of a shock but they appear to have survived."