Mila Kunis is the latest celebrity whose cell phone has been hacked, and the hacker is leaking several pictures of a seductive Justin Timberlake ... TMZ has learned.

Four pictures have been leaked, including two which show Justin -- one, laying shirtless in a bed, and another in which J.T. is jokingly sporting a pair of pink panties over his head. Kunis is not featured in either of the pics.

There's another photo of Mila in a bathtub, but all you see is her head. And then there's another photo of a male which is explicit in nature, although his identity is a mystery.

There are also some texts and the hacker claims they reveal exchanges between Justin and Mila.

As we first reported, we're told Scarlett Johansson is going to the FBI today after nude photos of her that were hacked from her cell phone were published this morning.