THE White House is typically revered as a symbol of leadership, democracy and power.

But it has today been described as a “crime scene” following revelations the probe into Russia’s interference in the US election has been widened to include allegations President Donald Trump attempted to obstruct justice.

American political commentator Seth Abramson said Special Counsel Robert Mueller — who is investigating the alleged Russian interference in the election and possible collusion with the Trump campaign — was “focusing on crimes that occurred in the White House”.

“The White House is now a crime scene,” Mr Abramson posted on Twitter.

In a pivotal shift in the investigation that has riveted Americans like no other for decades, senior intelligence officials have agreed to be interviewed by investigators working for Mr Muller, according to The Washington Post.

The newspaper reported on Wednesday that director of national intelligence Dan Coats, head of the National Security Agency Mike Rogers, and former deputy director at the NSA Richard Ledgett, had agreed to be interviewed by Mr Mueller’s investigators as early as this week.

The move to investigate the US President comes after Mr Trump fired FBI director James Comey on May 9, according to the The Post.

(16) Not to put too fine a point on it—the White House is now a crime scene. Mueller is focusing on crimes that occurred in the White House. — Seth Abramson (@SethAbramson) June 15, 2017

Mr Comey told Congress last week he believed he was fired by Mr Trump to undermine the agency’s Russia probe.

An event reportedly of particular interest to Mr Mueller is an exchange on March 22, when Mr Coats told associates that Mr Trump had asked him to intervene with Mr Comey to get him to back off the president’s former national security adviser Mike Flynn as part of the FBI probe into the Russia affair.

A few days later, Mr Trump individually asked Mr Coats and Mr Rogers to issue public statements to the effect that there was no evidence of co-ordination between his campaign and Russia. The Post said both men refused the President’s request.

Mr Trump’s lawyer Marc Kasowitz issued a statement saying the FBI was behind the Post story and called the leak “outrageous, inexcusable and illegal.”

But Mr Kasowitz did not deny its accuracy.

White House spokesman Mark Corallo said: “The FBI leak of information regarding the President is outrageous, inexcusable and illegal.”

Ranking Democrat on the Senate Intelligence Committee Mark Warner told reporters that Mr Mueller had briefed senators Wednesday on his work.

“I’m going to acknowledge we had a meeting with the special counsel Mueller, but I’m not going to get into the contests,” Mr Warner said.

A spokesman for Mr Mueller declined to comment.

Several legal experts said that Mr Comey’s testimony, about Mr Trump telling him he expected loyalty and hoped he could drop an investigation of a former top aide, could bolster obstruction of justice allegations against the President.

After Mr Comey’s testimony, Mr Trump said he had been vindicated because it was confirmed he had been told on three occasions that he was not under investigation.

An obstruction of justice finding could form the basis for Mr Trump’s impeachment but such a step would face a steep hurdle because it would require approval by the US House of Representatives, which is controlled by the President’s fellow Republicans.

— with wires

megan.palin@news.com.au