Conservative Party leader David Cameron's Witney constituency party has admitted receiving more than £7,000 in invalid donations, it was revealed today.

The Witney Conservative Association agreed to forfeit the sum to public funds because the benefactors were not on the UK electoral roll.

The news is embarrassing for the Tory leader, who has been scathing in his criticism of the Labour Party over the recent "proxy" donors scandal, involving property developer David Abrahams.

However, aides insisted that the incident was the result of a "genuine mistake".

Records on the Electoral Commission website show that two donations received by the association on August 21 were subsequently found to have been impermissible.

Roger Fletcher gave £5,900, while Geoffrey Dobbs provided an auction prize worth £1,500.

A total of £7,400 was handed to the commission on November 16.

A Conservative Party spokesman said: "As soon as we became aware that these two donations were not permissible we declared and voluntarily forfeited them to the Electoral Commission."