Jas Prince, son of Rap-a-Lot CEO J. Prince, is generally credited with discovering Drake.

He signed him over to Birdman in 2009, after a huge bidding war. Now, for the second time, Jas is suing Baby and Cash Money for the royalties he was promised.

Jas says he has only received 2 million of the estimated 40 million Drake has generated for CM -- which is far less than he was promised.

According to TMZ, the new legal documents demand Birdman open his books so Jas can determine what he is owed.

This follows the sinister diss track Jas's dad directed toward Baby and Slim last week.

"I will not allow for it stay on my track record that Cash Money took anything from me and my son," J. threatened in the spoken word track. "Do right by me, and pay every penny due."

Jas's suit could simply be in his own self-interest. But opening Birdman's books could benefit Drake too, so there's always a chance the old friends are working together on this one.

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