No Russian collusion in Trump's 2016 election campaign: Mueller

Special Counsel Robert Mueller has not found any evidence suggesting Russian collusion in US President Donald Trump's 2016 election campaign, according to Attorney General William Barr.

Barr made these statements in his summary of the Special Counsel's 22-month-long investigation which culminated on Friday. He sent the much-awaited summary of the Mueller report to the US Congress on Sunday.

"The Special Counsel's investigation did not find that the Trump campaign or anyone associated with it conspired or coordinated with Russia in its efforts to influence the 2016 US Presidential Election," Barr said in his summary.

"While this report does not conclude that the President committed a crime, it also does not exonerate him," the Attorney General added.

This comes as a relief to the US President who has decried the Mueller investigation on numerous occasions, labelling it as a witch hunt and also alleging Presidential "harassment".

The investigation into the possible Russian interference in Trump's 2016 Presidential run has seen charges being filed against 37 defendants, seven guilty pleas and one conviction. Reactions from Trump and the US Congress are awaited.

As part of his investigations, Mueller interviewed about 500 witnesses and obtained more than 3,500 subpoenas and warrants of various types. 13 requests to foreign governments for evidence were also made as part of the massive investigations.