A key member of Nick Clegg’s inner circle accepted a potentially illegal donation for the Liberal Democrats — and arranged a private meeting for the would-be donor with the Chief Secretary to the Treasury, an investigation by The Telegraph discloses.

An undercover reporter posing as a wealthy Indian businessman was told he could donate money to the party via a “cousin”. He was also advised to spread gifts among other family members and even backdate a cheque to the party. This would allow the true source of the donation to remain hidden on the official register of political donations.

The donation was sought by Ibrahim Taguri, the party’s former chief fund-raiser, who was standing for MP in Brent Central and boasts that his campaign is the “third best-funded” in the country. Mr Taguri has since stood down as a party candidate and from his Lib Dem race equality role while claims against him are investigated.

Earlier this month, he accepted a cheque on behalf of the party for more than £7,500 from the “proxy donor” and the senior Liberal Democrat said the money would “open doors”.

He then invited the undercover reporter to a fund-raising dinner and private meeting with Danny Alexander.

At the meeting, the Chief Secretary to the Treasury encouraged the fake businessman to provide further financial support to the party, but said that he did not want “to intrude on the details” of his donations. In a private discussion, Mr Alexander said: “I just want you to know that I, personally, am very, very grateful for what you are doing and for what you are offering to do… It genuinely will make a difference to the results of the election.”