From the Fox Nation on May 26 (a story that apparently has since been scrubbed from their website):

The Fox Nation post linked to an article on the birther site WorldNetDaily that reports that Trump told WND senior reporter Jerome Corsi during a telephone conversation that he believes the long-form birth certificate produced by the White House is fake.

Previously:

Fox Nation Again Hypes Trump's Birtherism

Fox Nation Promotes Trump's Ongoing Birther Claims

Fox Continues to Celebrate Trump's Birther Claims

Fox Nation Promotes Trump's Claim That Obama May Be A Muslim

Right-Wing Media Hype Conspiracies About Obama's Long-Form Birth Certificate

WND: “Trump Pumps Corsi For Latest” Birther Info