Former Democratic presidential candidate Hillary Clinton said in an interview on Monday that she wouldn't rule out contesting the 2016 election if the probe into Russian interference proves that the depths of Moscow's meddling go even further than is already known.

"No, I wouldn't rule it out," Clinton told Terry Gross, longtime host of US radio broadcaster National Public Radio (NPR) interview program "Fresh Air."

The ex-secretary of state added, however, that there were few legal avenues to challenge a US election.

"There are scholars, academics, who have arguments that it would be [possible], but I don't think they're on strong ground," Clinton said.

In spite of that, Clinton did note that it was "interesting" that the recent election in Kenya had its results declared invalid – considering the campaign of incumbent Uhuru Kenyatta was in part orchestrated by the data mining company Cambridge Analytica. The firm is owned by wealthy Mercer family, which also has ties to the pro-Brexit campaign and US President Donald Trump.

'The weaponization of information'

"There's now an investigation going on in the UK, because of the use of data and the weaponization of information," Clinton told Fresh Air.

"They were involved in the Trump campaign after he got the nomination, and I think that part of what happened is Mercer said to Trump, "We'll help you, but you have to take Bannon as your campaign chief. You've got to take Kellyanne Conway and these other people who are basically Mercer proteges."

Clinton, who won the popular vote by a margin of nearly three million, also renewed calls to abolish the electoral college.

"I was sitting listening to a report on the French election and the French political analyst said, 'You know in our country the person with the most votes wins, unlike in yours.' And I think that [the electoral college] is an anachronism. I've said that since 2000."

Russia investigation convenes grand jury

Although it has already been confirmed that Russian sources were behind a series of widespread "fake news" campaigns targeting Clinton during the run-up to last November's vote, Special Counsel Robert Mueller is still conducting his investigation into whether the Trump campaign colluded with Moscow.

In August, US media reported that had convened a grand jury as part of the probe – the first step to levelling criminal charges.