London Marathon charity donations made through the Virgin Money Giving website increased by two-thirds to nearly £14m in 2011.
The donation website, which opened in 2009, processed donations related to the event worth £13.88m in 2011, including Gift Aid, up from £8.3m in 2010.
More than 350,000 people made London Marathon donations through virginmoneygiving.com, compared with 214,405 in 2010. The average donation of £31.34 was virtually unchanged.
Strong take-up of Gift Aid in 2011 meant £2.2m was added to the total. Eighty-six per cent of all the donations were Gift-Aided.
A Virgin Money Giving spokesman said: "The Virgin London Marathon is the biggest annual fundraising event in the world and the contribution of online giving services is helping it to continue to grow."
A spokesman for the online donation website JustGiving said its figures were not yet available. A spokeswoman for Bmycharity said it did not collate figures for the event because charities set up their own pages through the site.