Britney Spears' new song for the Smurfs 2 soundtrack has appeared online.

The pop princess has contributed 'Ooh La La' for the film, which is due to be released on July 31.

The song has reportedly been made with the likes of Dr Luke, Ammo and Bonnie McKee.

Speaking previously about the song, Spears said: "I have always loved the Smurfs as a kid and now my boys are the biggest Smurfs fans ever. I wanted to surprise them with a song in the movie. I know they'll think it's Smurftastic!"

The Smurfs 2 is set to star the voices of Neil Patrick Harris, Jayma Mays and also Katy Perry.

As previously reported, Spears recently confirmed long-standing rumours that she will perform a Las Vegas residency.