The killer clown craze was started by Warner Brothers as a viral marketing stunt, according to a former employee.

Charged with creating a “cheap, viral campaign” for the upcoming 2017 remake of the movie IT, the viral marketing manager says his team created the killer clown idea as a way of “making clowns scary again.”

The stunt didn’t get off the ground smoothly though, with “six or seven” attempts at kickstarting the craze falling flat.

“We sent clowns out six or seven times to scare people, but it wasn’t catching. Nobody gave a shit. We needed to up the ante so we had to go a bit dark.”

Claiming he was part of the marketing team who created the idea, the former employee explains that in order to make people “sit up and take notice” the clowns had to target young children.

Referring to the 5-year-old boy in Greenville, South Carolina who told his mother that two killer clowns in the woods attempted to lure him into an abandoned house, the insider said, “That’s when we hit paydirt.

“It got reported in the local news and picked up nationwide. We did another couple of stunts and one of them got reported too.

“Then it blew up and took on a life of its own. We were all joking that we’re going to have Made Clowns Scary Again on our gravestones.”

'Creepy clown' incidents should be taken 'quite seriously' by law enforcement, White House press secretary says. https://t.co/ICVDdDyvjk pic.twitter.com/rALkC8ZCk6 — ABC News (@ABC) October 4, 2016

Asked why Warner Brothers have distanced themselves from the craze, the former employee said, “Well they have to. They are not going to own up to something that has taken on a much darker edge than they expected. But this is why I’m pissed with them.

“The stunt is the biggest triumph of my career so far and now I can’t boast about it and use it on my resumé because according to Warner Brothers it doesn’t exist.”

“They are loving it though. Ka-ching.”