Sonisphere 2014 headliner Metallica are set to showcase a new song this weekend, with an update on their Facebook page saying: "Working out the kinks in the new song that we'll be debuting in South America in a couple of days." The news was accompanied by a picture of the band fine-tuning the new track in a studio.

Earlier this year drummer Lars Ulrich confirmed the band are working on a new album: "The jams we've done so far have been super exciting and it's gonna be fun putting this record together in the next year.Death Magnetic is our obvious point of reference. Going good for good riffs, good energy, interesting progressions, with a melodic sensibility."

At Knebworth this summer Metallica are playing a "By Request' set made up of songs voted for by the fans. But they will also play one new song. Could that be the track they showcase in South America this weekend?