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