Mark Kranz, Fox News' chief financial officer until his retirement last August, has been offered immunity from prosecution in exchange for his cooperation with the investigation, two sources with knowledge of the matter.
The investigation centers on questions about whether 21st Century Fox misled investors by hiding payments to Fox News employees who alleged that they were sexually harassed by Ailes. As CFO, Kranz was directly involved in preparing the company's financial statements and is thus potentially a key witness in the investigation, the sources said.
Kranz's lawyer declined to comment on the matter. Spokespeople for the Department of Justice and the U.S. Attorney's Office for the Southern District of New York, which is handling the investigation, also declined to comment.
Ailes resigned from Fox News last July amid an internal investigation into multiple sexual harassment allegations against him, including those detailed in a lawsuit brought by former anchor Gretchen Carlson. Anchor Megyn Kelly, who has since decamped to NBC, also told investigators that Ailes harassed her a decade ago.
As CFO from 2004 to 2016, Kranz oversaw financial statements for Fox News and might therefore have been aware of any company payments made to women who accused Ailes of sexual harassment.