A Scotland Yard spokesman said it was understood the search for the couple had ended when they arrived at the home of friends at Bridge North, Ontario.
Andrew and Monica Nickell, who were on holiday, were informed by Canadian police officers of their daughter's murder.
Detectives are expected to stage a reconstruction of the last movements of Rachel Nickell this Wednesday. Scotland Yard hopes to jog the memories of anyone who might have seen the man who sexually assaulted and stabbed Miss Nickell, 23, to death and then assaulted her two-year-old son.
Police also hope to issue a photofit picture or artist's impression of a man seen washing his hands in a stream near the scene.