It is thought that a journalist from the broadcaster hacked into the emails of John Darwin.
Media regulator Ofcom is to investigate Sky News over its admission that one of its journalists hacked into the private email account of "canoe man" John Darwin and his wife Anne.
Earlier this month the broadcaster said it stood by its decision after ruling the action was in the public interest.
Sky News said the evidence it discovered was handed to police and used in the successful prosecution of Darwin's wife Anne for insurance and pension fraud.
A spokesman for Ofcom today told Press Gazette the investigation was self-initiated and that is had not received a complaint from any of the parties involved.