Guitarist Kirk Hammett has confirming that Metallica are steadily working on their first album since 2008, Gigwise reports.

Speaking to Billboard, Hammett revealed of the work they have created for the album thus far: “The songs are ever-changing at this point. Nothing is etched in stone. We still have a lot of material have to sift through, still. We have well over a dozen songs and we still have well over two or three hundred riffs, too, so it's hard to say at what point we actually are in in the project. I don't think we hit the middle point yet. I would say we're at the 25 percent point, maybe 30 percent point. It's hard to say, but I mean we are working on it and there are songs and we're making plans to write more songs and record.”

Hammett then added that the band become very consumed by recording saying: “Whenever we go into the studio, it becomes such a huge sort of thing in our lives that it does take on monstrous proportions. It takes up a lot of space in our lives.

Metallica are one of the headline acts for this year’s Reading and Leeds festival following an outstanding set at last year’s Glastonbury.