Police are waiting to see if the wife of canoeist John Darwin will return to the UK to face questioning, after he was charged with deception offences.
John Darwin was presumed dead for more than five years.
Detectives have urged Anne Darwin, 55, who is thought to be in Florida, to make contact with them.
Mr Darwin, 57, reappeared last weekend after being presumed dead since 2002.
He is due before Hartlepool magistrates on Monday charged with obtaining life insurance money by deception and making an untrue statement to get a passport.
Mrs Darwin recently moved to Panama, having sold the family home in Seaton Carew, Teesside.
A photograph showing her with her husband in Panama last year has not been independently verified.
Anne Darwin sold the couple's home in Seaton Carew
In a statement on Saturday, Det Sgt Iain Henderson, of Cleveland Police, said police did not know when Mrs Darwin planned to return to the UK.
He said police would be making enquiries to trace her if she did not get in touch, though it had not been decided whether this would involve sending officers abroad to find her.
Speaking at a press conference, he said: "We would ask Mrs Darwin, if she's watching this, to make contact with the police and to approach us at the earliest opportunity so we can speak to her.
"Cleveland Police will be making enquiries to trace her and speak to her regarding the investigation."
Mr Darwin was declared dead by the Hartlepool coroner in 2003. He had not been seen since March 2002 before he walked into a police station last weekend, claiming amnesia.
He was arrested at his son's house in Basingstoke, Hampshire, on Tuesday on suspicion of fraud.
Police said an application would be made on Monday to keep him in custody, where he was said to be "fit and well" on Saturday night.
Det Sgt Henderson said he could not say whether further charges would be brought in the case or whether the investigation would be extended to include other members of the Darwin family.
The couple's sons, Anthony and Mark, earlier released a statement saying they had been through a "rollercoaster of emotions" after finding out their father was alive.