Purchases made over the web represented 9.9% of all UK retail sales in June, up from 6.8% a year earlier, according to the Office for National Statistics (ONS).
The agency estimated e-commerce sales at £376.3m in June 2010. One year later, web sales had increased significantly - by 49% to £560.5m.
In the same period, all retail sales in June recovered from May's slump: volumes rose 0.7% last month, which surpassed market expectations but only recovered half the previous month's 1.3% drop.
When explaining the slight increase, the ONS said there was "anecdotal evidence" of summer sales starting earlier this year.