The email which Kim Dotcom claimed was proof of a conspiracy against him is a forgery, the Serious Fraud Office has said.
The Herald can today report for the first time that the SFO investigated the email, which emerged on the eve of the 2014 election claiming then-Prime Minister John Key was involved in a conspiracy to get Dotcom.
It is also a definite statement rejecting any possibility the email is genuine.
In a statement, the SFO said: "The SFO confirms that it carried out an investigation into this matter. As a result of that investigation, the SFO is satisfied that the email was a forgery."
Dotcom said today that he still believed the email to be genuine and was surprised the SFO was able to be so definite.
"I believe the email to be real," he said.
The purported email was from Warner Bros chief executive Kevin Tsujihara to the Motion Picture Association of America's Asia-Pacific president Michael Ellis.
It was dated the day Key met Tsujihara and was in the midst of Immigration NZ's consideration of Dotcom's residency.
It read: "We had a really good meeting with the Prime Minister. He's a fan and we're getting what we came for. Your groundwork in New Zealand is paying off. I see strong support for our anti-piracy effort.
"John Key told me in private that they are granting Dotcom residency despite pushback from officials about his criminal past. His AG will do everything in his power to assist us with our case. VIP treatment and then a one-way ticket to Virginia.
"This is a game changer. The DOJ is against the Hong Kong option. No confidence in the Chinese. Great job."
A Warner Bros senior vice president told the Herald at the time: "Kevin Tsujihara did not write or send the alleged email, and he never had any such conversation with Prime Minister Key. The alleged email is a fabrication."
A spokeswoman for the MPAA said: "Mike Ellis never received this alleged email or discussed this matter with Kevin Tsujihara."
Dotcom said today that the email was "easy to discredit" because it did not have "headers" - detailed information which shows the internet protocol address from which it was sent or the relays and servers it passed through.
As a result, he "could not use it at the Moment of Truth" - the event he organised at the Auckland Town Hall the week before the 2014 election. There, whistleblower Edward Snowden, Julian Assange of Wikileaks and journalist Glenn Greenwald made claims of mass surveillance of New Zealanders.
"It was a huge disappointment and distracted from the bigger picture: The Government and its participation in mass surveillance," Dotcom said.
The email is back in the spotlight thanks to a new taxpayer-funded documentary into the Dotcom case. Kim Dotcom: Caught In The Web, which premiered at the SXSW film festival in the United States this week, includes the German-born entrepreneur talking about the origins of the email.
In the documentary, he says: "That email, I know it comes from hacker circles. You know about the famous Sony Hack. The same people who were responsible for that hack, were responsible for this hack."
The email saga began months before the 2014 election, when Dotcom promised he would reveal evidence of a conspiracy between Hollywood studios and the New Zealand Government to have him granted residency and then arrested for extradition.
With less than a week to go before election day, the Herald received a copy of the email.
The contents supported the theory Dotcom had voiced since his 2012 arrest by the FBI on charges of criminal copyright violation. He claimed he was granted residency as a ploy to lure him to a country from where it would be easier to extradite him.
The Herald broke the story about the supposed email after obtaining a copy and confirming with Dotcom it was the proof he intended to release at the Moment of Truth.
The Herald then reported that every person named in the email - except Dotcom - had called it a fake. When it came to the Moment of Truth, Dotcom was unable to present any evidence of the conspiracy he said was aligned against him.
Key was approached for comment today but declined to make any statement. In 2014, he said he had "never heard of" Dotcom in 2010. "I hadn't been briefed on the guy."
Kim Dotcom: Caught In The Web director Annie Goldson told the Herald there was a lot riding on the purported email at the time it was made public.
"Given the then PM John Key had promised to resign if either mass surveillance or his knowledge of Kim Dotcom prior to the raid of 2012 was proven, the stakes were very high."
Laila Harre, who was leader of the Kim Dotcom-backed Internet Party at the 2014 election, was recently quoted as saying she could not rule out that the email was genuine.
Today, she said: "My view of it has always been, I was convinced that Kim was convinced it was authentic. I've got no more information than that."
Investigators familiar with SFO methods told the Herald the definite statement the email was a forgery revealed an deep and forensic-style investigation.
One investigator with SFO experience said the agency would have sought statements or interviews from the named executives and access to the servers. It would have studied the format and style of the email to see if it was consistent with where it was supposed to have come from.
Checking servers of the purported recipient and sender would be essential too. "If you did both parties and neither had it, that would be a strong basis to support the argument it was a forgery."
He said the inquiry would also have involved each person believed or known to have contact being considered.
"Someone has put that document together for a reason," he said.