US Attorney General Barr claims FBI spied on Trump campaign

"I think spying did occur," Barr told a Senate panel on Wednesday in Washington. "I need to explore that."

After two years of Democrats pursuing Trump with claims that he collaborated with the Russians during the 2016 elections, which an inquiry finally said did not happen, Barr stirred the muddied political waters anew with the claim.

"Spying on a political campaign is a big deal," he said, but went on to add during questioning by senators on the sub-committee that deals with budgetary matters: "I have no specific evidence that I would cite right now. I do have questions about it."

Democrats accused Barr of trying to legitimise the accusations of spying on the Trump campaign.

The party's Senate leader, Chuck Schumer, said: "Perpetuating conspiracy theories is beneath the office of the Attorney General."

Separately on Wednesday, Trump called the surveillance "an attempted coup".

He told the media: "This was an attempted takedown of a president. And we beat them."

The President said that the surveillance "was started illegally" and "everything about it was crooked. Every single thing about it. There were dirty cops".

Barr did not say what the spying was or how he thought it was carried out, but he appeared to be referring to the surveillance of Carter Page, a former Trump campaign adviser, that began in 2016 under former President Barack Obama's administration.

Although a judge signed the warrant for the surveillance after Page left the campaign, it was controversial because the spying was said to have been based on information provided by Christopher Steele, a former British intelligence agent, whose work was paid for by the Democrats.

Page, who ran a company that advised Russian businesses, has not been charged with any crime.

Mark Warner, a leading Democrat on the Senate Intelligence Committee, in a tweet said that Barr "giving a wink and a nod to this long-debunked 'spying' conspiracy theory is irresponsible".

In the current political scene, the two sides have turned a 180 degrees in their opinion of the FBI.

The Democrats and the liberals, who are now its defenders, have traditionally been wary of the agency that had resorted to dirty tricks against civil rights leader Martin Luther King and spied on anti-war activists during the Vietnam War. On the other hand, the Republicans were the uncritical supporters of the FBI.

Page, who had at one time worked for the Wall Street company, Merrill Lynch, in Moscow, had according to the dossier compiled by Steele, met a Russian official.

Trump and his supporters have claimed that a "deep state" of established Washington insiders were working against him as he was an outsider.

The Democrats kept up their demand for the publication of the full report of Special Counsel Robert Mueller, who investigated the allegations of Trump's collusion with Moscow. Barr, who has the right to decide on publishing it, has released a summary that said that Trump had been exonerated of the Russian collaboration allegations, but did not reach a conclusion if was guilty of obstruction of justice.

Democrats have said that they do not trust Barr's summary, which dashed their hopes of ousting Trump on the charges of the Moscow link.

Barr said that he would release it next week after redacting portions of it with intelligence material and secret testimonies that cannot legally be made public. He also agreed to share some of those redacted portions secretly with lawmakers.