David Hasselhoff thinks Justin Bieber is a "cool guy".

According to People.com, he said: "We had a lot of fun, and he's a cool guy.

"You'll hear more about it, but we're just keeping it quiet because it's really a cool video, and we had a blast."

The 62-year-old actor also quickly deleted a post from his Twitter account following the shoot in which he shared that he, Justin and Australian pop star Cody Simpson had enjoyed a "great day" filming the video.

He said yesterday(21.09.14): "What a great day @CodySimpson @justinbieber Emile our director for new video ... signing t shirts for charity! RESPECT!"

David also posted an image of himself wearing his iconic Baywatch shorts and jacket, however it is not known if the photo is related to the mystery project.

Meanwhile, Cody, 17 - who is working on a duet album with Justin - recently jumped to the defence of his new pal following his altercation with Orlando Bloom in July.

The 'Boyfriend' hitmaker had to dodge a punch from the 'Lord of the Rings' star at a party in Ibiza after reportedly making a reference to the actor's ex-wife Miranda Kerr - who he was romantically linked with during their marriage - but Cody insists his misdeeds can be put down to his youth.

He said: "Obviously we're all young and he gets himself into some stuff sometimes.

"He's a person I'd go to for everything. He's like a big brother.

"He has the world in his hands as he does a lot of good as well. I've got all good things to say."