Sir Michael Caine kept bursting into song on the set of Journey 2: The Mysterious Island, Vanessa Hudgens has revealed.

The British acting legend, who plays grandfather Alexander Anderson in the sequel to 2008's Journey To The Centre Of The Earth, would sing Beyonce and Katy Perry tunes, to the surprise of his younger co-stars Vanessa and Josh Hutcherson.

"It's crazy, he's like such a legend, but at the same time he's so hip and so in the know. He was singing Beyonce - I was sitting next to him in-between set-ups and he was singing 'Baaaby you're a fiiiirework' and I was like, 'Are you singing Katy Perry?'," she recalled.

"He told me about a documentary they did on her music video, and I'm thinking, 'I'm in my 20s, I should know this, and I'm being filled in by Michael Caine'."

She added: "He's such an incredible guy, with such an amazing energy, and is so sweet and welcoming. I adore him."

Vanessa, who has released two albums, said she's focusing on her acting career right now.

"I'll definitely go back at some point - I love music, I love performing, I love creating the alter-ego. All the aspects of it are just so much fun," she said.

"It's definitely taken a back seat recently as I've been focusing on films, and diving into some more intense stuff, but I feel like when the time's right, it's definitely something that will be revisited."

:: Journey 2: The Mysterious Island is in cinemas now.