Senate Democrat leader Chuck Schumer calls for removal of head of House Intelligence Committee Devin Nunes

The US Senate Democratic leader, Chuck Schumer, has called for the removal of Republican Representative Devin Nunes as chairman of the House of Representatives' Intelligence Committee.

Mr Nunes, whose Congressional committee is investigating potential ties between President Donald Trump's campaign and Russia, visited the White House the day before announcing he had information indicating Trump's transition team may have been subject to what he called "incidental" intelligence gathering by US officials.

“Chairman Nunes is falling down on the job and seems to be more interested in protecting the president than in seeking the truth,” Mr Schumer said in a Senate speech.

Neither Mr Schumer or fellow Democrats in the House or Senate have the power to remove and replace Mr Nunes, but in his floor speech he urged House Speaker Paul Ryan to do so if Mr Ryan "wants the House to have a credible investigation" into the Trump campaign team's possible ties to Russia.

Nunes spokesman Jack Langer said in a statement that Mr Nunes “met with his source at the White House grounds in order to have proximity to a secure location where he could view the information provided by the source.”

Mr Nunes has said he will not reveal his source which has led to several questions regarding who let him onto the grounds and who granted him access to the documents.

He claims that the documents he viewed regarding conversations about Mr Trump and his team may have been distributed around the government improperly and in a press conference the next day he explained that he felt certain names of the Trump team may have been unnecessarily "unmasked".

However, he also said during the press conference that he felt the surveillance was "legal".

White House Press Secretary Sean Spicer said the White House was not aware Mr Nunes was on the grounds that day but that he was "not concerned" about the matter.

Mr Spicer claimed if two people who are cleared to share classified information share it, then "it's not a leak."