Police and paramedics were called out to reports of a man covered in blood, staggering close to a canal, only to find he was filming a zombie movie.
Officers and ambulance crews had rushed to the Aire and Calder canal near Stanley Ferry in Wakefield, West Yorkshire.
But they arrived at the scene to find film makers shooting a zombie movie, reports the Daily Telegraph.
Nicola Morter, 31, of Barnsley, was producing The Eschatriology for Safehouse Pictures UK which she co-founded with partner Damian.
She said the incident happened as around 30 actors and extras were made up as zombies on the last day of a five-day shoot.
She said: "The zombies were walking across a bridge over the canal. I'm guessing either a dog walker or someone driving past has spotted one.
"The zombies do look good. They are very old school. They are rotting, covered in bites, blood and mud and do look scary."
PC Tim Saxon said: "We got called to a report of a male covered in blood staggering around. We had to investigate what it was and take it on its own merit as it could have been anything.
"We had to walk through fields and didn't know what it was we would find. Then suddenly we saw nine zombies and a film crew and they had some very realistic make-up.
"It was a relief no one was injured and we would prefer to be safe than sorry. They were just as surprised to see us and were quite jovial."