The appearance of two familiar figures ignited a short-lived frenzy among journalists perched outside the Lindo Wing of St Mary's Hospital.
The regal looking pair stepped out of a blacked-out land rover and made their way to the top of the entrance of the private hospital, but the police officer at the door spotted they were not the Duke and Duchess and accompanied them back down the stairs.
The lookalikes were part of a stunt by tabloid newspaper, The Sun.
More top news
The Royal Marine shot a Taliban fighter in 2011 and had his initial murder conviction quashed earlier this month.
The report found one man had voted twice in the EU referendum and a Tory councillor who had been jailed for submitting a false address.
Weather set to improve with plenty of sunshine by Saturday