A maternity clothes label launched by a Hampstead mum has been enjoying a sales boom after the Duchess of Cambridge was snapped wearing one of its outfits in her first official picture with baby Prince George.

Fashion firm Seraphine, which was launched a decade ago by Parisian-turned-Hampstead mother Cecile Reinaud, sold out of its £46 Jolene dress within two hours of the image appearing last week.

The Duchess was pictured in the frock by her father Michael Middleton with the Duke of Cambridge, baby Prince George and dog Tilly.

Seraphine, which has shops in Hampstead High Street and Kensington, also enjoyed a 2,600 per cent boost in web traffic, selling more than two months’ worth of dresses in just 48 hours.

Ms Reinaud, who has two sons and lives in Hampstead, was quick to make the most of the “Kate effect”.

She said: “Kate is now an international role model for an entire generation of new mums and everyone dreams to look as beautiful, natural and glowing as she did in those photographs. By buying our dress, women are able to get closer to the dream she represents.”