Two White House officials were responsible for handing Devin Nunes information suggesting Donald Trump's team were spied on by US intelligence agencies, reports suggest.
The revelation is likely to renew pressure on Mr Nunes, the chairman of the House of Representatives Intelligence Committee, who has already been accused of being too close to Mr Trump - despite being in charge of a supposedly independent inquiry into the US President's alleged links with Russia.
The California congressman sparked controversy earlier this month after claiming he had seen evidence that backed up Mr Trump's claims he had been spied on by US agencies. He refused to reveal the source of his information, saying only that it had come from whistleblower.
The New York Times has now suggested the information was passed to him with the help of two White House officials: Ezra Cohen-Watnick, the senior director for intelligence at the National Security Council, and Michael Ellis, a national security lawyer in the White House Counsel's Office.
White House Press Secretary Sean Spicer declined to comment on the latest reports.
At a press conference on 22nd March, Mr Nunes declared he had seen evidence suggesting US spies had "incidentally collected" information on some of Mr Trump's associates while looking into matters unrelated to the Russia inquiry.
His claim came almost three weeks after Mr Trump posted a series of early-morning tweets alleging he had been wiretapped on the orders of his predecessor, Barack Obama.
"Terrible! Just found out that Obama had my "wires tapped" in Trump Tower just before the victory. Nothing found. This is McCarthyism!", he wrote.
"How low has President Obama gone to tapp my phones during the very sacred election process. This is Nixon/Watergate. Bad (or sick) guy!"
The accusation was widely ridiculed and was dismissed by Mr Obama's spokesman, intelligence agencies and a number of prominent Republicans.
Mr Nunes then surprised commentators by claiming he had seen evidence that members of Mr Trump's transition team were indeed unwittingly included in US surveillance operations.
"I recently confirmed that, on numerous occasions, the intelligence community incidentally collected information about U.S. citizens involved in the Trump transition," he told reporters.
"Details about U.S. persons associated with the incoming administration, details with little or no apparent foreign intelligence value, were widely disseminated in intelligence community reporting."
Mr Nunes was later forced to admit he had discussed his findings with Mr Trump before informing members of his own congressional committee. That led some members to criticise their chairman and question his priorities.
Mr Nunes is in charge of one of several congressional investigations into allegations that Russia attempted to influence the US presidential election in Mr Trump's favour.