John Podesta has reiterated his theory the FBI deliberately sabotaged Hillary Clinton's election campaign, saying there were forces within the bureau that 'wanted her to lose'.

In an interview earlier this month, Podesta, who was Clinton's campaign manager, pointed to the Russian hack of the DNC and the FBI's lackluster response to it as proof of his theory.

Compared to its 'painstaking' dig into Clinton's emails and its bold decision to reopen an investigation into her use of them days before the polls opened, he said it the bureau seemed stacked against their campaign.

'There are at least forces within the FBI that wanted her to lose.

'I'm not sure they really understood the alternative but they wanted her to lose,' he told Bloomberg's John Heilemann at the Newco Shift Forum earlier this month.

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Podesta (left in December) said there were 'forces within the FBI' (director James Comey is pictured, right) that wanted Hillary Clinton to lose the election

Podesta said he found it 'inexplicable' at first that the FBI took a soft approach to the DNC hack which resulted in the leak of thousands of emails from inside the Clinton campaign.

Despite being aware of the potential threat from Russian hackers, Podesta said the bureau did not send any agents to the committee's headquarters and instead left a voicemail with its IT department.

'It's inexplicable that they were so casual about first the investigation about the Russian penetration of the DNC emails, they didn't even bother to send an agent to the DNC, they didn't call anybody senior, they left a couple of messages at the IT help desk saying you might want to be careful.

'It was very hard to get any information from them.'

By contrast, agents were aggressive in their investigation of Clinton's use of a private email server.

Podesta made the comments during an interview with Bloomberg's John Heilemann earlier this month (above)

Podesta said it was 'inexplicable' that the FBI didn't send agents to the Democratic National Committee to investigate the hack of its emails. Above, Clinton is pictured giving her concession speech weeks later

Podesta pointed to the bureau's aggressive investigation into Clinton's emails and the decision by Director James Comey to reopen the probe days before the polls opened

The announcement by director James Comey to reopen the probe just 10 days before the polls open was even more intrepid, he said.

'(He) ended up dropping this bombshell in the middle of the election against the advice of the Justice Department, against the long term practice of Democratic and Republican administrations...it's inexplicable.'

Comey said there ought to be a 'deep investigation' into Trump's ties with Russia

Podesta also called for a 'deeper investigation' into Trump's ties with Russia, alleging the president's camp knew about the country's attempts to thwart Clinton's campaign in advance.

'I think that needs to happen is a much more serious investigation of whatever collusion existed between the Trump campaign, the Russians and Assange.

'I think there needs to be a deeper investigation of what did they know, when did they know it, who were they talking to, and it's fairly clear that at least they had foreknowledge of some of the activities that were being run against our campaign.'

Podesta first shared his suspicion that the FBI acted deliberately against Clinton during the election campaign in an opinion piece for The Washington Post in December.

The article was titled 'Something is deeply broken at the FBI' and mapped out his concerns with the bureau's seemingly one-sided approach to the incidents which plagued the campaign.

At the forum earlier this month, he said another possible explanation for why it came down so heavily on his candidate was that Comey was trying to keep on the right side of influencers within it.

'(It has) become a 'cover your a**' ass organization and there was pressure coming up from underneath him.'