It's been reported that there's been an increase in security at Leavesden studios just outside London following a threatening phone call made on Friday.

The studio has confirmed that a hoax call was received last week, but it hasn't resulted in any increase in the already tight security there.

And there hasn't been a trebling of on site security staff.

'No further action'

A spokesperson for Warner Bros. told CBBC Newsround Online: "As with all responsible companies we take the well being of those within our employment, particularly children, very seriously.

"We have in the past received the odd hoax telephone call, but because of our strict security policies we always report these incidents no matter how seemingly trivial, to the relevant authorities.

"In this case as with previous hoax calls, no further action has been taken nor will be required".

Hertfordshire Police also told Newsround that they had not drafted in extra officers or police dogs to patrol the studio.