Donald Trump's lawyers have reportedly begun considering the authority to grant pardons as investigations into Russian collusion gather pace. The Washington Post reported that Trump has been looking into how to grant presidential pardons to friends, family and political aides.

An adviser told the Post that the president wasn't looking to specifically pardon individuals, but was simply curious about the process. The adviser said: "This is not in the context of, 'I can't wait to pardon myself.'"

It comes as authorities probe Trump's business connections as part of its investigation into possible collusion between his election campaign and Russia.

As well as discussing pardons, the Trump team is looking into ways to scale back the investigation by former FBI boss Robert Mueller, who is acting as special counsel for the Department of Justice to head up their Russia investigations.

Trump's aides are said to be looking for ways to discredit Mueller to either undermine what he produces or have him removed. But Republicans are wary because Trump firing Mueller would cast another dark shadow over Washington months after he sacked James Comey as head of the FBI.

Senator Marco Rubio: "Yes, it would be a mistake to fire Bob Mueller because I think he is a highly credible individual who will do a good job."

When the Senate intelligence committee chair Richard Burr was asked if Trump should fire Mueller, he replied: "I don't think the president can fire Bob Mueller."

What are the investigations?

The Department of Justice, now guided by a special counsel, who is Mueller, is looking into the ties between the Trump campaign and Russia and any possible cover-up. At the same time, there are numerous committees on Capitol Hill looking into possible Russian influences on the election.

This includes the Senate Intelligence Committee who, under their purview, have taken both public and closed testimonials from Comey.

Two other congressional groups, the Senate Judiciary Committee and House Oversight and Government Reform Committee, are looking into former national security adviser Michael Flynn, as well as the firing of Comey.

Despite the departure of Comey, who believes he was fired because of the FBI investigation into the Trump campaign's ties to Russia, the bureau is continuing due process.

The emails that the president's son Donald Trump Jr released, which detailed his meeting with a Russian lawyer who promised damning information on Hillary Clinton, is the latest twist that investigating committees are keen to delve into.

Trump Putin
US President Donald Trump and Russia's President Vladimir Putin shake hands during a meeting on the sidelines of the G20 Summit in Hamburg, Germany. Saul Loeb/AFP/Getty Images