Eminem. (AP File)

Rap superstar Eminem will give fans a double treat this year - by serving up two new albums by the end of 2009.

The Without Me hitmaker, real name Marshall Mathers III, has been working on his highly-anticipated chart comeback - the follow-up to 2004's Encore - for months.

Relapse, recorded with his mentor and superproducer Dr. Dre, was originally expected to be released in late 2008/early 2009, but Eminem has now picked a mid-May date for the disc.

And the star reveals his studio sessions have been so productive, he's already got Relapse 2 in the works, which he plans to release just months after Relapse.

Eminem tells MTV, "A lot of people were expecting Relapse to drop last year. I was one of them. Then Dre and I went back in the studio in September for a few days, and that turned into six months.

"We were on such a roll; we wound up with a ton of new music produced by Dre. Putting out Relapse 2 will let everyone get all of the best stuff."

Eminem's continued popularity was confirmed last month when his new single, Crack A Bottle featuring Dr. Dre and 50 Cent, shot to the top of the Billboard singles chart after shifting 418,000 download sales to take the number one slot.