London-based Index Ventures has led a $9 million (£5.7 million) investment round into female online fashion retailer Nasty Gal.

Nasty Gal now sits alongside similar Index-backed retail businesses such as Net-a-Porter, ASOS, Etsy and Stylistpick.

The Series A funds will be used by Nasty Gal to invest in technology, operations, creative curation and editorial design, as the company looks to expand its global footprint.

Founded in 2006 in San Francisco by Sophia Amoruso as a seller on global auction site eBay, the business initially sold one-off items of vintage clothing that Amoruso found. Since then the business has grown its revenues by 500 per cent each year to its current level of $28 million.

Amorouso says that Nasty Gal has ‘tapped into a unique fashion sensibilty’ that has managed to capture girls’ imaginations.’

She adds, ‘For me, it wasn’t about raising capital, but about finding the right partner. Index was an obvious fit; the stars aligned and my decision was an easy one.’

Danny Rimmer, partner at Index Ventures, comments, ‘We look forward to helping [Amoruso] and the rest of the outstanding management team in this next phase of growth to fully capture the opportunity she uncovered starting in the thrift stores and flea markets of San Fransisco. Nasty Gal is on its way to becoming a defining fashion brand.’