Like-for-like retail sales in central London in June were 8.7% higher than the previous year.
London retail sales outperformed the country as a whole, which saw retail sales decline by 0.4% in June. Central London retail sales are up 6.8% on a like for like basis between April and June.
The British retail Consortium said that retail footfall was only slightly weaker than in May but that it remained above its year-earlier level, helped by clearance sales and high petrol prices which discouraged out-of-town shopping trips.
The BRC said that clothing and footwear sales had benefited from clearance events and continued discounting. Designer fashions outperformed the rest of the sector.
Tourists from western Europe remained the main overseas shoppers largely because they were taking advantage of the strength of the euro against sterling. US and Japanese visitors were still discouraged by the weak dollar and yen.
BRC director general Stephen Robertson said: "This is a strong result for London. The mood among central London customers is clearly different from the rest of the UK. Londoner's higher average incomes, spending by overseas visitors and the rising costs of driving to shopping centres further afield have pushed up shopper numbers and spending. Much of that is being driven by early sales and the most widespread price cutting in recent history but the contrast with the rest of the UK, which has experienced negative like-for-like growth in three of the last four months, is stark."
Helen Dickinson, head of retail at KPMG, said: "Central London has once again outperformed the UK. However, the like-for-like sales increase of 8.7% over a year ago has been driven by outperformance by certain businesses in the capital - some of the department store in particular - and should not be seen as representative of greater London as a whole. Those that have done well have bought forward their summer Sale activity in order to drive footfall and increase sales."