"Their legal theory has been that we hid the fact that we had a problem with Roger", Gerson Zweifach, Fox's general counsel, wrote in the email, referring to the prosecutors and Mr. Ailes, "and now it will be applied to O'Reilly, and they will insist on full knowledge of all complaints about O'Reilly's behavior in the workplace, regardless of who settled them".
In response to a New York Times story published Saturday, 21st Century Fox says it knew of the settlement but not the monetary amount.
In February, aware of Wiehl's claims and the settlement, 21st Century Fox offered O'Reilly a new four-year contract at $25 million a year, up from about $18 million.
The star anchor was dismissed in April after the Times revealed that Fox News had paid about $13 million in settlements to bury numerous similar allegations over the years, sparking widespread outrage.
The $32m (£24m) settlement was paid to former Fox legal analyst Lis Wiehl, according to the New York Times.More news: North Korea crisis: Tillerson says diplomacy will continue
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In trying to contain yet another scandal at the much scandalized, many times publicly remorseful and much sued FNC, the parent company today also reacted to the latest revelations with more promises that things are getting better.
Even though company executives were aware of O'Reilly's alleged transgressions, they planned to keep him on at the company and extended his contract in February.
Ms. Wiehl agreed to destroy all communications between her and Mr. O'Reilly and eventually signed an affidavit dated January 17 retracting the allegations and promising not to sue, the report said.
Mr. O'Reilly told The New York Times that he had been receiving threatening messages during his time at Fox News and was forwarding some of the material to Ms. Wiehl since she was one of his attorneys, according to the report.
"This is crap, and you know it", O'Reilly told the Times, when asked about the settlement.
Wiehl accused O'Reilly of harassment and "a nonconsensual sexual relationship", according to the Times, which cited unnamed sources briefed on the settlement. O'Reilly was sacked in April over initial reports of his settlements with five women over similar allegations.