Redstone raging

Sumner scion at Aunt Shari’s throat

Sumner Redstone’s granddaughter has again lashed out her aunt Shari, angered this time by the sale of a former drive-in movie lot owned by the family holding company.

“When he was mentally competent, my grandfather would never have sold this property at any price,” Keryn Redstone said in a statement Wednesday. “This is another example of my aunt Shari’s manipulation of my grandfather now that he is mentally compromised.”

National Amusements Inc. — which holds the assets to Sumner Redstone’s $42 billion media empire, principally Viacom and CBS — recently sold the West Roxbury, Mass., property, which now houses a Home Depot, for $34 million.

Keryn’s Wednesday salvo is just the latest spat in a feud that pits NAI and Shari against Keryn and Viacom leadership.

Shari’s side contends NAI, which controls 80 percent of Viacom, was within its rights when it moved in May to oust Viacom Chief Executive Philippe Dauman and a Via- com director from the board of NAI — a move, that if successful, essentially removes Dauman from any say in the future of Viacom or CBS.

NAI also moved in June to oust five Viacom directors.

Keryn and Dauman’s Via- com team claim Shari is exploiting the mental incompetence of her 93-year-old father to wrest control of his media empire.

Keryn’s lawyer, Pierce O’Donnell, called his client “alarmed by the audacity with which her aunt Shari Redstone has unlawfully seized control.”

After noting no one outside of Shari’s orbit has been allowed to see Sumner in months, Keryn described him as “listless” when she last visited him, on Valentine’s Day.

Sumner’s mental capacity will be further addressed on Friday in a Delaware Chancery Court hearing — the second in a suit brought by ousted Viacom director Fred Salerno.

In June, during the first hearing, the judge was willing to wait for a Massachusetts court to establish Sumner’s mental capacity. rmorgan@nypost.com