Will Chris Rock make an appearance on Eminem's upcoming album? A leaked photograph is fueling rumors that the comedian and the rapper are in the midst of a collaboration.

Rock posted a picture of himself last week in a studio where Enimem was presumed working on his as-yet-untitled eighth solo album. An accompanying tweet from Rock read, "In the studio with Em don't sleep."

Further speculation arose when Rock appeared on yesterday's edition of the fuseTV program United States of Hip Hop, where he gave an equivocal answer -- "Uh... I can't really say" -- to questions about his possible presence on the follow-up to 2010's Recovery.

If it happens, it would not be Rock's first rap album cameo. He was featured on a monologue on the song Blame Game from Kanye West's critically acclaimed 2010 album My Beautiful Dark Twisted Fantasy.

"I was on the Kanye record, maybe I'm on the Eminem record," Rock continued. "You never know."

Eminem was also photographed working with rapper Big Sean in April.

The as-yet-untitled album is due out after Memorial Day, "but we're not exactly sure when," Shady Records President Paul Rosenberg revealed to Billboard in February. "He's been working on it for some time."

The rapper will also be making the rounds on the European festival circuit, including the U.K.'s Reading and Leeds Festivals. "We've got some dates locked in for him to perform live in Europe in August," Rosenberg said, "so we're trying to see what else lines up."

Check out the video of Rock's fuseTV interview!