The estate of Jimi Hendrix is suing the heirs of the trailblazing guitarist’s former bandmates after they allegedly threatened to sue for “millions of pounds” in unpaid royalties dating back decades, Billboard reports.

In December, Lawrence Abramson, a British lawyer representing the families of the Jimi Hendrix Experience bassist David Noel Redding and drummer John Graham “Mitch” Mitchell, sent a cease-and-desist letter that claimed they owned a stake in Hendrix’s music and threatened to sue for infringement.

In a case filed on 18 January in Manhattan, the Hendrix estate and Sony Music, the exclusive licence holder of Hendrix’s catalogue, requested a legal declaration stating that they owed nothing.

They said that the claims were invalid given that Redding and Mitchell signed “broad general releases” and agreements not to sue in exchange for “significant monetary consideration” after Hendrix’s death. Their lawyers claim that Redding signed in April 1973 and Mitchell in September 1974 agreeing to release the Hendrix estate from legal claims, Rolling Stone reports.

The Hendrix estate and Sony said that the settlements “specifically” concerned the band’s recordings and that there had been no claim by Redding and Mitchell or their successors “for almost half a century … concerning the copyright ownership, exploitation of these recordings by plaintiffs or payments of royalties”.