US media tycoon hit by family feud

A granddaughter of Sumner Redstone alleged on Wednesday that the ailing media mogul is being manipulated by his daughter, vowing to help stop her purported bid to "seize" his corporate empire.

The daughter of Sumner Redstone’s estranged son Brent, Keryn Redstone makes bitter accusations against her aunt Shari Redstone. Her statement has deepened the family drama, setting the stage for a heightened battle for control of holdings that include the CBS television group and media conglomerate Viacom.

The granddaughter has allied herself with the 93-year-old billionaire’s ex-girlfriend Manuela Herzer, who has been waging a battle to have him declared incompetent.

In a statement released by her lawyer Pierce O’Donnell, Keryn Redstone said she and Herzer have been prevented from seeing Sumner Redstone even though "we are two of the persons who were the most devoted to his welfare and protecting him."

"Shari and her family have managed to totally isolate and effectively kidnap, brainwash and take advantage of my grandfather due to his debilitated state of mind and frail health," the statement said. Shari Redstone and her three adult children "have succeeded in reversing decades of my grandfather’s careful estate planning and are poised to seize control of Viacom and CBS," it added.

"I will soon be announcing legal steps to join with the Viacom directors in our common cause to liberate my grandfather from Shari’s clutches and protect my fellow trust beneficiaries and myself from her machinations

However, when asked about Wednesday’s allegations, a spokeswoman for Shari Redstone called them “not worthy of a comment”.