The top-level investigation is set to drag in numerous prominent New Zealanders.
They include property developer Tony Gapes, Shareholders' Association founder and former Financial Markets Authority (FMA) member Bruce Sheppard, high-profile lobbyist and PR agent Carrick Graham and Cameron "Whaleoil" Slater.
Collins resigned yesterday as Justice Minister after a leaked email from Slater claimed she had been "gunning" for Feeley while she was minister in charge of the SFO.
She will remain as MP for Papakura and is set to stand in the general election.
Further emails, expected to be released today, are believed to show Graham - who was at one time employed by Hotchin - and another right-wing blogger, Cathy Odgers, alias Cactus Kate, were behind attacks on Feeley.
As former managing director of Hanover Finance, Hotchin was at the time under investigation from the SFO and FMA for his role in the failure of Hanover in 2008.
About 16,000 people with investments totalling more than $500million lost most of their money following the failure of Hanover and related companies and the sale of assets to Allied Farmers.
Correspondence obtained by hackers who targeted the Whaleoil site showed Slater and Odgers were working together with Graham to attack Feeley while he was responsible for investigating Hanover Finance.
Feeley is now chief executive of the Queenstown Lakes District Council.
The email released yesterday set out plans to discredit Feeley and was sent to a "Mark".
Several sources claim that was Hotchin.
It was also sent to a "Carrick" - Carrick Graham who was representing Hotchin at the time.
Collins denied any knowledge of the smear campaign, instead claiming she had been the victim, but was forced to resign after a series of controversies just three weeks out from the general election.
Slater wrote a series of highly critical blogs about Feeley in late 2011.
They covered allegations that could have damaged Feeley's reputation in the eyes of the public.
On October 7, 2011, he wrote a series of blogs titled "Staff Issues at the SFO".
One had claimed 23 staff had left the department at that time during his tenure.
Slater had written: "What sort of cowboy culture has been bred by Five Fingers Feeley at the Serious Fraud Office?"
It is understood emails to be released will show pressure was exerted on the SFO and the FMA to close their investigations into Hanover.
Odgers was a figure in the Dirty Politics book and last week her Hong Kong-based employer Jeeves Group confirmed she was no longer a consultant for them "by mutual consent".
It is understood that decision was linked to emails being released by the hacker today, which are expected to show the bloggers were being paid to discredit Feeley.
Slater says he "embellished" references to Collins in the damning leaked email that led to her resignation as a minister.
Last night Slater revealed he would lay a complaint with the Privacy Commissioner over Prime Minister John Key releasing the email that led to Collins' resignation.
He claimed Key had "breached my privacy", a charge he also aimed at Dirty Politics' author Nicky Hager.
Graham said he would not comment.
"I don't discuss who my clients are or the work I do for them. Facilitate is a private company and that's all there is to it."
In a statement last night State Services Commissioner Iain Rennie said he was "extremely concerned" at the suggestion that Collins had undermined Feeley.
"It is important that chief executives and ministers mutually support each other to carry out their respective roles.
"I am therefore extremely concerned by an allegation that a minister has associated with third parties to discuss influencing my assessment of a Public Service chief executive. If true, this would be wholly unacceptable."
Gapes, a former close friend of Hotchin, was also among the victims of the smear campaign.
Gapes was shocked to find he was fingered in a smear campaign to undermine his credibility as a potential witness against the troubled Hanover company. "A lot of it is all falling into place now," said the Auckland developer.
Gapes said he went from being a developer with a low media profile to suddenly appearing in a constant stream of negative stories.
"It was obvious I was someone Hotchin was worried about when he was being investigated by the SFO," said Gapes.
Sheppard last night said emails between Graham and Slater revealed plans to deliberately target him.
The emails were sent at the same time as the former Shareholders' Association president was involved in defamation against Hotchin and fellow Hanover boss Eric Watson.
One of Collins' most relentless opponents, Joe Karam, says the country is better off with her out of Cabinet.
"May she be long banished to the backbenches," Karam said.
The SFO did not gain enough evidence to prosecute anyone associated with Hanover.
Hotchin and five others, including Watson, will face a High Court trial next year after they pleaded not guilty to civil charges brought by the FMA.
Good, bad and murky views
Opinion was split in Papakura when the Herald on Sunday visited the electorate shortly after Judith Collins' resignation was announced.
"I'm very upset about it, actually, because she's such a good minister," said John Smith.
Christine Baty was also unshaken in her support for the embattled MP. "We need somebody stirring and feisty," she said.
"She's in your face. I like having somebody like that there."
But Sanjay Arora said her resignation was "about time".
"She should have been sacked earlier. I don't know why John Key took so much time."
Rita Rai said she voted for Collins at the last election but would not do so again.
"Things have been a little too murky."
The Dirty Politics scandal has tarnished Collins in Danny Cairns' view.
"When she first started I actually thought she was quite good, even though I didn't vote for her. After what's happened over the last few weeks, I'm glad she's gone."
Tweeters twitch over minister
Judith Collins' resignation created plenty of debate on social media, especially Twitter where the #judithcollins hashtag proved popular.
Lizzie Marvelly @LizzieMarvelly:
"So Slater was basically bragging with puffed up claims in the email. What a silly little man. Why you would associate with him is beyond me."
Imperator Fish @ImperatorFish:
"BREAKING: Judith Collins removes all mirrors from her house, as she begins hunt for the person who destroyed her career."
James Elliott @JamesElliott8:
"I agree with Slater - Judith Collins death by a thousand cuts, all self-inflicted."
Lew @LewSOS:
"BREAKING: Judith Collins has unfriended Cameron Slater on Facebook; relationship status changed to "it's complicated"."
Greg Boyed @GregBoyed:
"If nothing else after #JudithCollins resignation you'd have to look back with head shaking awe at the stickability of Hekia Parata."
Russell Brown @Publicaddress:
"So: mindful of the polls, they needed a pretext to dump Collins, but it couldn't come from Hager's book. So this email turned up. Amirite?"
Barry Soper @barrysoper:
"Emergence of the Collins execution email convenient for Nats given opinion polls overwhelmingly said she should go!"
- Herald on Sunday
