Jordan Fenster, Jordan Fenster and Mark Lungariello | Rockland/Westchester Journal News

Peter Carr/lohud

A new political action committee apparently supporting Westchester County Executive Rob Astorino's re-election bid appears to be funded by Robert Mercer.

Peter Carr/The Journal News

Mercer is known as a prominent supporter and backer of Donald Trump's 2016 bid for the presidency and is the financial powerhouse behind Breitbart News.

State elections filings show that a newly registered super PAC called “Win for NY” received two donations of $500,000 each on Oct. 23, as Politico initially reported.

Expenditures show $412,000 spent on ads supporting Astorino.

A website, winforny.org, features an ad attacking Astorino's Democratic opponent, George Latimer.

“Meet Albany politician George Latimer," the ad says. "Latimer voted to raise your property taxes 46 percent, but news reports show Latimer didn’t pay his own property taxes — $46,000 on one of his family’s homes. Textbook hypocrisy — Latimer raises your taxes but doesn’t pay his own.”

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The ad refers to unpaid taxes on a house owned by Latimer's wife in Rye. Some taxes on the house haven't been paid dating back to 2012, when Latimer's wife inherited the house from her mother. Latimer has blamed the unpaid taxes on a dispute within his wife's family.

Astorino has continually hit Latimer on the unpaid taxes and called a news conference last week calling on Latimer to pay the taxes.

Jon Greenfield, a spokesman for the Latimer campaign, said Astorino should condemn Mercer or explain why he'd accept his support.

“Astorino’s claim of representing Westchester values is another lie – Trump mega-donor Robert Mercer puts his billions behind extremists like Steve Bannon and Rob Astorino, while promoting white nationalism, anti-Semitism even claiming that ‘African-Americans had it better before the civil rights era,'" Greenfield said.

Mercer believed the Civil Rights of Act of 1964 was a "major mistake," according to The New Yorker magazine, which quotes a source saying Mercer believed African-Americans were financially better off before the civil-rights movement

Astorino's spokesman, Bill O'Reilly, declined to directly address the super PAC or Mercer's involvement, though he did echo the ad's message.

"It's no wonder that people are weighing in on George Latimer's dishonesty and tax hypocrisy" O'Reilly said in an email to The Journal News/lohud.com. "Here's the ranking member of the Senate Education Committee skipping the state Education Budget vote to jet off to a London holiday while refusing to pay five years in back school taxes. Who wouldn't be outraged by that?"

The Astorino campaign and the PAC are barred from directly working with one another.