Thousands of Ryan Gosling fans were fooled into thinking the movie hunk had become a dad after a fake Facebook.com message suggested he had adopted a baby last year.
Pranksters behind the hoax profile set up in The Notebook star's name sent devotees into a spin on Father's Day after sharing a photo of the actor holding a child.
The accompanying caption read: "This father's day, I've decided to tell the story of how I became a father."
The fake message went on to detail how the infant had "brought me so much joy", until a custody fight with the baby's biological father ended in despair: "Of course, I put up a fight, but he won. That 1 year of being his father taught me how to love unconditionally."
The prank attracted almost one million 'likes' from followers and prompted many to gush about the actor's "decision", but the page, which has not been verified by Facebook bosses, has since been dismissed as bogus.
The Father's Day post also directed fans to another website, which encouraged them to purchase T-shirts to win the chance to spend a day with Gosling.
The pranksters also claimed all proceeds would go towards the Orphanage Home Foundation, a charity which does not exist.
The Hollywood star, who does not have any children, has yet to comment on the bizarre Facebook stunt.