AP source: Billionaire David Koch has died at age 79

FILE - In this Aug. 30, 2013 file photo, Americans for Prosperity Foundation Chairman David Koch speaks in Orlando, Fla. Koch is stepping down from the Koch brothers network of business and political activities. The 78-year-old cited health reasons in a letter distributed to company officials on Tuesday morning. (AP Photo/Phelan M. Ebenhack, File)

WASHINGTON (AP) — Billionaire David Koch has died at age 79. Koch was a major donor to conservative causes and educational groups.

A person close to the Koch family told The Associated Press on Friday that Koch had died. The person wasn’t authorized to discuss the death and spoke on the condition of anonymity.

Together with his older brother, Charles, the Kochs were best known for a vast political network they built that became popularly known as the “Kochtopus” for its far-reaching tentacles in support of conservative causes.