The largest single donation to Yvette Cooper's Labour leadership campaign comes from a former donor to the Conservative party.
Businessman Peter Hearn gave Cooper £75,000 to support her campaign for the Labour leadership. According to the latest listing Cooper made in the register of MPs' interests, Hearn's donation makes up over a quarter of the £260,000 she has raised to fund the "Yvette for Labour Leader" campaign.
However, figures given to the Electoral Commission show that Hearn also gave £10,000 to the Conservative party in the run-up to the 2010 election.
Hearn is a multi-millionaire accountant behind PSD Group, an executive recruitment firm specialising in high-level jobs in banking, finance, and other sectors. His donation was registered this month, although the actual donation was made in July.
Since donating to the Conservatives in 2009-10, Hearn has become a major Labour donor: He gave the Labour head office donations worth £279,000 over 2014-15.
Hearn has switched his donations between parties more than once. Before his Conservative donations, back in 2007 he gave Labour £5,000.
Labour headquarters is currently working to make sure the leadership election "is not for those who support other parties and is only for those who support the Labour party", with many would-be voters complaining they have been wrongly excluded from taking part in the vote.
BuzzFeed News asked the Cooper campaign if they had any concerns about taking money from a man who has switched support between different parties.
A spokesperson for the campaign said that Hearn was a longstanding Labour supporter:
We are very grateful to Peter Hearn and all those who have donated to the Yvette For Labour campaign. To characterise Peter as a Tory switcher is plain wrong. He has been a major donor to the Labour party for several years and a Labour voter all his life.
In 2010 he was so keen to stop the divisive and unpleasant politics of George Galloway that he supported both the local Labour and Conservative candidates fighting to prevent George Galloway's Respect party gaining his local seat. He is unequivocally a Labour supporter.
Electoral Commission records do show Hearn giving £5,000 to the Tower Hamlets Labour party in 2007. However, they also show that he gave more money, and more often, to the Conservative party in 2009-10.
He helped fund the Conservative election campaign in Poplar, where George Galloway was standing against Labour's Jim Fitzpatrick and Tim Archer for the Conservatives. Fitzpatrick won the seat, with Archer coming second and Galloway third.
Hearn's political donations are registered at the Electoral Commission under a variety of spellings – Peter Hearn, Peter J Hearn, and even a misspelled Peter Hearne. The Electoral Commission confirmed to BuzzFeed News that all these donations are registered to the same address and that they are all from the same man.
BuzzFeed News has approached Peter Hearn for comment.