House Intelligence Chairman Devin Nunes said at a press conference Wednesday that Donald Trump and his transition team may have been surveilled following the presidential election.

According to Mr Nunes, some communications from the Trump team – and possibly Trump himself – were subject to legal, “incidental” collection before his inauguration. He did not specify whether the then-President-elect’s communications were specifically targeted for collection.

Mr Nunes believes the surveillance to be legally collected, but nevertheless said he is “alarmed” by the discovery. He claimed the intercepted communications were widely disseminated among intelligence agencies, revealing the names of several Trump associates in the process.

Mr Nunes chairs the House Intelligence Committee's ongoing investigation into Russian interference in last year’s election. He told reporters he uncovered the potential surveillance while reviewing intelligence reports.

The representative visited the White House Wednesday afternoon to brief Mr Trump on his findings. Mr Trump said after the meeting that he felt “somewhat” vindicated by Mr Nunes’s announcement.

House intelligence committee Democrats said they were not consulted about the information before the news conference.

"If accurate, this information should have been shared with members of the committee, but it has not been," said Adam Schiff, the top Democrat on the House Intelligence Committee.

Mr Nunes at first said none of the surveillance was related to the investigation of Trump campaign ties to Russia. However, Mr Nunes said later he could not be sure whether other information existed elsewhere related to Russia.

The leaders of the main House investigative committee said separately on Wednesday they had asked the White House and FBI for documents regarding Flynn's foreign contacts with Russia, Turkey and others.

After briefing Mr Trump, Mr Nunes told reporters outside the White House, “I think the president is concerned, and he should be.”

Mr Trump previously accused former President Barack Obama of surveilling him during the election, tweeting, “Terrible! Just found out that Obama had my 'wires tapped' in Trump Tower just before the victory. Nothing found. This is McCarthyism!”

Mr Nunes categorised the surveillance as “normal intelligence reporting.” He did not see any evidence of physical wiretapping, and did not know whether any surveillance had occurred at Trump Tower. He focused mainly on the alleged “unmasking” of Trump and his associates in the intelligence reports.

“This is normal intelligence reporting,” Mr Nunes said. “The question is, should [Trump] himself or others been put into [intelligence] reports? I don't know the answer yet, but we’re going to try to get to the bottom of it.”