In Corus UK Ltd v Mainwaring EAT/0053/07, the EAT held that an employer did not act unreasonably when it failed to interview an informant who alleged that a fellow employee was malingering, as that allegation merely triggered a fair investigation. In addition, it was not necessary for the employer to seek medical evidence from a specialist consultant, it being reasonable for it to rely on evidence about the employee's medical condition from a GP.