LONDON, June 1 (Reuters) - Britain's Nigel Farage, a leading Brexit campaigner, is a "person of interest" in the U.S. investigation into possible collusion between Russia and Donald Trump's presidential campaign, the Guardian newspaper reported on Thursday, citing unidentified sources.

The British newspaper said Farage had not been accused of wrongdoing and was not a suspect or target of the U.S. investigation.

But it said the former leader of the United Kingdom Independence Party had "raised the interest" of FBI investigators because of his relationships with individuals connected to both the Trump campaign and Wikileaks founder Julian Assange.

"This is absurd, truly absurd," a UKIP spokesman said when asked about the report. "To my knowledge, the only serious Russian politician that Nigel has spent time with is Garry Kasparov." (Reporting by Kate Holton; editing by Guy Faulconbridge)

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