Paul Ryan has hit back at President Trump's claims the FBI planted a spy in his election campaign 'for political purposes'.

The House Speaker said he has seen 'no evidence' of so-called 'deep state' spying during a press conference on Wednesday.

Asked about Trump's assertion that he has the power to pardon himself in the event Robert Mueller's collusion probe finds dirt on him, Ryan added: 'Obviously, the answer is he shouldn't, and no one is above the law.'

Paul Ryan says he agrees that the FBI did not plant a spy in Trump's campaign for political purposes, but added that he wants to 'run every lead down'

Ryan spoke out to defend Trey Gowdy, a fellow Republican and friend, who is a member of the House Intelligence Committee and was briefed on what Trump calls 'spygate' last month.

After the meeting, Gowdy said the spying was 'in no way connected to Trump' and was instead looking for collusion with Russia, which Trump has denied doing.

'It was President Trump himself who said, No. 1, 'I didn't collude with Russia, but if anyone connected with my campaign did, I want the FBI to find that out,'' Gowdy said.

'It looks to me like the FBI was doing what President Trump said I want you to do — find it out.'

That did not stop the President's supporters from subsequently going after Gowdy, a fact which clearly rankled Ryan who has largely avoided contradicting Trump since clashes early on in his presidency.

Trump claims the FBI spied on his presidential campaign as part of a deep state attempt to help Hillary Clinton win the election in what he has dubbed 'spygate'

Speaking on Wednesday, Ryan said: 'I think Chairman Gowdy's initial assessment is accurate … but we have some more digging to do.

'I have seen no evidence to the contrary of the initial assessment that Chairman Gowdy has made, but I want to make sure we run every lead down and make sure we get final answers to these questions.'

Trump has branded the controversy 'spygate' and has repeated the line that it is 'worse the Watergate'.

He claims the Obama administration planted 'eyes and ears' in his campaign team to help Hillary Clinton win the election.

Former Director of National Intelligence James Clapper has denied Trump's campaign was the target of any probe.

The FBI was looking into Russian interference in the US election and that line of inquiry led them to Trump, he said.