The woman became suspicious about the reappearance of Darwin, who was presumed drowned after he disappeared near Hartlepool in 2002.
Darwin's wife Anne recently moved to Panama, and Darwin presented himself at a London police station claiming to be suffering from amnesia.
The woman typed 'John, Anne and Panama' into Google and found a picture of the couple on a website called Move to Panama dated July 2006.
"I would like to nominate them for the 'World's Dumbest' awards," she told The Mirror.
"Not only were they photographed, but the date was on the picture. It was just too good to be true.
"I just blinked and there they were. I rang police in Cleveland. The man on the other end said: 'You're joking.'"
Darwin has since been arrested by police and his wife has confirmed that the picture is genuine. She has said that she will fly back to the UK and cooperate with the authorities.
"I do not want to live my life as a fugitive. I will have to go back because I will not have any life here," she said. "But I guess my life anywhere is going to be pretty awkward now."
Missing canoeist found by Google
By Iain Thomson on Dec 7, 2007 7:14AM