ET has the latest...

Janet Jackson's new album, Number Ones, is in stores today, and now a source is telling ET that the estate for the late Michael Jackson is at war with Janet over one of the songs on the album.

The song in question is called "Make Me" and features a lyric that reads, "Don't stop till you get it up." The source has told ET that Michael's estate is questioning Janet's right to use the lyric because of its similarity to his song "Don't Stop 'Til You Get Enough," featured on Michael's album Off the Wall.

We've reached out to Janet's camp, who have not yet responded, while the attorneys representing the estate's special administators John Branca and John McClain tell ET they are unaware of it and will get back to us.

The Jackson family has clashed with Michael's estate previously. Back in August, family matriarch Katherine Jackson was allowed to challenge Branca and McClain without risk of jeopardizing her position as a beneficiary in his will.

And just earlier this month, Katherine withdrew her objection to Branca and McClain being the administrators of the will, while patriarch Joe Jackson filed a motion claiming that the lawyers have a "conflict of interest" and should be removed as administrators of the late singer's will.