The continuing legal battle between Marvin Gaye’s family and pop star Robin Thicke got even uglier yesterday after the Gaye estate filed a suit claiming that Thicke and his producers not only stole from Gaye’s song “Got To Give It Up” for the mega-hit “Blurred Lines,” but that many of Thicke’s other songs bear a suspicious resemblance to Gaye’s work.

The lawsuit stems from legal proceedings filed by Thicke as a sort of pre-emptive strike once people pointed out the resemblance between “Blurred Lines” and “Got To Give It Up.” In August, Gaye’s son alluded to the possibility that Thicke had stolen from the soul icon more than once throughout his career, and the new lawsuit makes Gaye’s son’s claims clearer.

The lawsuit alleges that Thicke lifted parts of Gaye’s song “After The Dance” for “Love After War,” the title track of Thicke’s 2011 album. The lawsuit also claims that Thicke has had a “Marvin Gaye fixation” throughout his career, citing various music critics who have noticed Gaye’s influence on Thicke’s music. Perhaps the most damning piece of evidence filed by Gaye’s family is an interview from GQ in which Thicke says that he and producer Pharrell Williams came up with “Blurred Lines” while trying to write a song similar to “Got To Give It Up.”

A spokesperson for Thicke’s label said that they have not looked over the lawsuit, but that a “leading musicologist” has advised that Thicke’s songs are not similar enough to Gaye’s work to warrant a lawsuit. Thicke himself has not said much on the issue other than that the quote in the GQ interview was taken out of context.