Issa London almost went bust because of the Duchess of Cambridge.

The fashion label struggled to cope with the mass demand for the sapphire-blue wrap dress the royal beauty donned for her engagement announcement to Prince William in November 2010.

Camilla Al Fayed, Issa's chairwoman, said: ''It absolutely sky-rocketed the brand on a global scale, but it was too much. Demand was so huge the business couldn't cope.

''If Kate wears a Zara dress, these huge companies have the backing to follow through. Issa was basically run by interns, students and Daniella [Helayel]. There was no business model.''

Camilla - who is the daughter of former Harrods owner Mohamed Al Fayed - became Issa's chairwoman in July 2011 after acquiring a 51 percent stake in the company, while founder and designer Daniella Helayel still has creative control.

Following the opening of the brand's first store in Japan, the plan is to invest in other companies.

Camilla added in an interview with The Times newspaper: ''That's definitely part of the long-term. Put it this way: I probably won't stop at Issa.''