The Republican head of a congressional committee investigating alleged Russian interference in last year's elections said on Monday he had received no intelligence evidence of contacts between Trump's campaign and Russian officials.

"Here at the committee, we still don't have any evidence of them talking to Russians," Devin Nunes, Republican chairman of the House Permanent Select Committee on Intelligence, told reporters. "And what I've been told by many folks is that there is nothing there."

Nunes, who was a member of Trump's presidential transition team, also said there was no need for a special prosecutor as being pushed by some Democrats and suggested it was unnecessary for President Donald Trump to release his tax returns to address allegations of business ties to Russia.

The Trump administration has been plagued by accusations and media reports several members of his campaign, including former campaign chair Paul Manafort, communicated with Russian officials during the election in which there were possible Russian attempts to influence the outcome in Trump's favor.

The Federal Bureau of Investigation (FBI) has been examining contacts between Trump advisers and Russia as well as Moscow's interference in the election, including hacking into the Democrats. Both the Senate and House intelligence committees are also conducting separate investigations.

Nunes' assertion prompted a sharp rebuke from the top Democrat on the House intelligence committee, spilling a partisan political fight out into the public.

Democratic vice-chair Adam Schiff said it was too early to prejudge any investigation before evidence had been presented.

"We haven't obtained any of the evidence yet. So it's premature for us to be saying that we have reached any conclusion about the issue of collusion," he said. "You don't begin by stating what you believe to be the conclusion."

Independent review 'recommended'

House Democratic leader Nancy Pelosi said Nunes' remarks raised concerns about Republican stonewalling the investigation.

Democrats have called for either a bipartisan committee or an independent prosecutor to investigate the Russia claims. Republicans have resisted Democratic calls for an independent prosecutor, but on Monday Representative Darrell Issa became the first Republican to break with the party on an independent investigation.

"I want the Trump administration to be successful and that starts with embracing high standards for openness and transparency," he said in a statement.  "Any review conducted must have the full confidence of the American people, which is why I recommended an independent review."

The partisan bickering comes as the "Washington Post" over the weekend reported that the Trump administration had asked Nunes and Senate Intelligence Committee Chairman Richard Burr to contact journalists in order to rebuff media reports of alleged cooperation between Russia and Trump officials. That story came after the "New York Times," citing intelligence sources, reported Trump campaign aides' contacts were with Russian intelligence.

The White House admitted last week it asked the FBI to help fend off what it called a "false" New York Times report by making its investigation public.

"This started with the FBI bringing it to us, bringing it to our attention, saying the story in the Times was not accurate," White House spokesman Sean Spicer said Monday.  "All we said is: 'That's great, could you tell other reporters the same thing you are telling us?'"

Nunes on Monday confirmed the White House had given him the phone number of a reporter, but denied allegations the administration had asked him to combat the media reports. Instead, he said he was promoting transparency.

cw/gsw (AFP, AP, Reuters)