Cheering New Yorkers greet William and Kate in first official visit
The real Kate Middleton (left) was in fact Christmas shopping in Chelsea at the time of the 'Kate and Wills' publicity stuntReuters

Shoppers in West London were left stunned when they thought they saw Kate Middleton and Prince William picking up Christmas bargains in their local discount store. The pair were thought to have been spotted in the High Street Kensington branch of Wilko on Friday, wandering the aisles and filling their shopping basket with giant teddy bears.

But the whole shopping trip appears to have been an elaborate publicity stunt, after it emerged that the couple were doppelgangers of the royals. Models Simon Watkinson, 33, and Heidi Aga, 34, are known as the UK's most popular 'Kate and Wills' lookalikes.

The pair are said to have caused a number of double-takes thanks to their striking resemblance to the Duke and Duchess of Cambridge. Shoppers used their mobile phones to film the lookalikes as they wandered through the store, picking up wrapping paper and Christmas cards.

They were also dressed the part, with Watkinson wearing William's trademark navy blue jumper, light blue collared shirt and tan chinos. Aga, meanwhile, looked the spitting image of Kate Middleton in a festive red coat and tartan skirt.

Harlen Holding, manager of the Wilko store in High Street Kensington, told the Mirror: "There were more than a few shocked faces and plenty of double-takes as 'Kate and Wills' paid their unexpected visit." He added: "The truth is, of course, that it wasn't actually the Duke & Duchess of Cambridge, but the UK's most popular Kate and Wills lookalikes."

The stunt came just on the same day the genuine Duchess of Cambridge was spotted doing a spot of Christmas shopping in nearby Chelsea. Wearing a long houndstooth coat and black skinny jeans, she was spotted walking through crowds of Christmas shoppers carrying a John Lewis carrier bag.

Earlier the mother-of-two was spotted entering department store Peter Jones – a branch of John Lewis, according to the Daily Mail. The real Prince William was nowhere to be seen during Kate's Friday afternoon shopping trip, however.

Kate Middleton shows off new hairstyle at Anna Freud Centre in first royal visit since Princess Charlotte birthIBTimes UK