Nigel Farage received £450,000 from the founder of pro-Brexit group Leave.EU in the year after the Brexit referendum.
Items paid for by Arron Banks included Mr Farage’s London home, his car and trips to the US to meet Donald Trump.
A spokesman for Mr Banks confirmed the amount and what it had been used for, saying it was an “honour to help”.
Asked about the funding following an investigation by Channel 4 News, Mr Farage – who now leads the Brexit party – said it was a private matter.
Speaking at the launch of the Brexit party campaign in Scotland, Mr Farage said he did not declare the it to the European Parliament because he was about to leave politics and had been seeking a new life