A mysterious group of pro-Brexit Scottish businessmen gave £425,000 to a Northern Irish political party that was largely spent on a pro-Brexit campaign outside Northern Ireland.
The Democratic Unionist Party took the cash from an obscure group called the Constitutional Research Council, fronted by a Conservative party activist and businessman called Richard Cook. Little is publicly available about the group, who backs it, or who funds it – it has no website and has only appeared in the media on one previous occasion.
Vote Leave, the official Brexit campaign group, has declined to comment on whether it knew in advance that the cash would be handed over.
The campaign group was subject to a strict spending limit of £7 million during the contest and could have broken the law if it coordinated spending with other pro-Brexit groups and broke this limit in the process. However, the Electoral Commission has repeatedly concluded it has no evidence that this was the case.
Under Northern Irish law political donors are not required to identify themselves publicly, but the DUP, which usually votes with the Conservatives in the Westminster parliament, bowed to persistent pressure and revealed the donor following reporting from the website Open Democracy. The site alleged that pro-Brexit individuals exploited a loophole in electoral law to spend money on last summer's EU referendum without declaring their identity – branding it "dark money".
Cook, the only identified individual associated with the Constitutional Research Council, did not respond to requests for comment. He stood as a Conservative party candidate for the Scottish constituency of East Renfrewshire in 2010, coming second to Labour's Jim Murphy. In addition, he has set up a string of businesses, including a short-lived investment management business owned by a Saudi prince who once ran the kingdom's intelligence agency.
Spending data release on Friday shows that once the DUP – which spent just £58,000 on its own general election campaign in 2015 – was in receipt of the £425,000 it set about spending the majority of the cash on pro-Brexit efforts in the rest of the UK.
Among the DUP expenditure was £282,000 spent buying a front-page advert in Metro on the eve of the poll, despite the fact the free newspaper is not distributed in Northern Ireland.
Staff at Metro, which has a distribution of 1.5 million and which was also paid to carry a pro-Remain advert on the following day, are understood to have been surprised when they received template with DUP branding, having expected it to be from Vote Leave.
The DUP says it made the tactical decision to book the UK-wide advert, although two sources suggested to BuzzFeed News that staff at the Vote Leave campaign were also aware in advance that the advert was going to be published. There is no suggestion that Vote Leave was involved in booking the newspaper advert, which was paid for by the DUP.
A Vote Leave spokesperson did not comment on whether staff at the main pro-Brexit group knew in advance that the advert had been booked by the DUP. There were close links between the two groups, with the DUP having one member on Vote Leave's board and seconding staff to the campaign.
Analysis by BuzzFeed News also shows how the DUP's other referendum spending has a remarkable symmetry with Vote Leave's own campaign spending, despite the restrictions on coordination between the two campaigns. The Northern Irish political party's second-biggest expense was a £99,600 contract for stickers, badges, advertising boards, and T-shirts with a Cambridgeshire company called Soopa Doopa. Vote Leave used the exact same supplier for the same purposes, spending £637,000 with the company.
The DUP also decided to spend £32,750 with a previously obscure Canadian online advertising business named AggregateIQ, which happened to be the in-house advertising provider for Vote Leave and received millions of pounds from Vote Leave and other affiliated campaigns for Facebook advertising.
A spokesperson for Vote Leave did not comment when asked twice whether the official pro-Brexit campaign was aware of the from the Constitutional Research Council's donation to the DUP or was involved in arranging it.
However, they did answer a separate question relating to the advertising services provided by AggregateIQ: "AggregateIQ provides election related technology and online advertising services for political organisations and candidates. They worked under contract for Vote Leave during the referendum and we were very happy with their services."
Labour MP Stephen Kinnock, who has already called for an investigation into Vote Leave's eve-of-poll £625,000 donation to a 23-year-old student – an arrangement which has been cleared by the Electoral Commission – told BuzzFeed News the DUP had broken the "spirit of the law" with its financial arrangements.
The DUP, which is currently fighting the Northern Irish Assembly election, initially refused to identify the financial backer. Party leader Arlene Foster originally insisted the money was "from an organisation in England that wants to see the Union kept and make sure we can have a United Kingdom". The party did not return a request for comment.
The Electoral Commission said it had no evidence of coordination between the campaigns: "For ‘working together’ rules to apply, and for there to be an allocation of reportable campaign spending, there needs to have been spending in accordance with a common plan or arrangement between the campaigners," said a spokesperson for the referendum regulator.
"We are examining campaigners’ spending returns to ensure that they are complete and accurate. Should we find evidence that spending should have been reported by any campaigners, we will consider it in line with our enforcement policy."