Russia's alleged hacking of the US election in favour of Donald Trump was "the political equivalent of 9/11", according to the former acting director of the CIA.

The spy agency said on Friday it had evidence that showed a link between the hacking of Hillary Clinton's emails and Russia, while officials from multiple agencies found connections between the Kremlin and Wikileaks.

According to Politico, former CIA acting director Michael Morell spoke out about the hack and said: "A foreign government messing around in our elections is, I think, an existential threat to our way of life. To me, and this is to me not an overstatement, this is the political equivalent of 9/11."

He added: "In a world with so many threats and challenges facing the United States and in a city where politics and policy disputes colour so many views, a president, if they’re going to be able to protect the country, they need someone to provide them with an objective, unbiased view of what’s going on in the world, and why it matters to them, and why it matters to the country.

"That job falls to the intelligence community led by the CIA, and that’s why the relationship between a president and the intelligence community and the CIA is so special.

"Right now that special relationship is being undermined."

Mr Morell was outspoken in supporting Hillary Clinton's candidacy, Politico said.

On Sunday a bipartisan group of senators, including former presidential candidate John McCain, said "the stakes are too high for our country" to allow evidence of the hack uncovered by the CIA to become a party-political issue, and that the American public must be kept better informed.