Former News of the World editor Andy Coulson's deputy broke down in tears as he was found not guilty of being part of a plot to hack phones in the race for scoops.
Neil Wallis, Coulson's right-hand man between 2003 and 2007, was on trial accused of being part of the scandal which led to the Sunday tabloid shutting down in July 2011.
An Old Bailey jury deliberated for four days before finding 64-year-old Wallis, of Chiswick, west London, not guilty of conspiring to hack phones.
Wallis is the last of the journalists from the tabloid to face legal action over the hacking it deployed in the hunt for exclusive stories on celebrities, royals and politicians.
The verdict comes nearly four years after Wallis's original arrest, on 14 July 2011.
The prosecution said it was inconceivable that Wallis did not know what was going on at the NoW since his boss and a number of other journalists in the newsroom had all been convicted of their involvement.
Among the high profile figures targeted by the NoW were princes William and Harry during their training at Sandhurst.
Former home secretary David Blunkett's secret affair with a married woman was exposed through hacking as was actress Sienna Miller's alleged fling with Bond star Daniel Craig.
The practice was first exposed in 2006 when NoW royal correspondent Clive Goodman and £100,000-a-year private investigator Glenn Mulcaire were convicted of hacking.
It resurfaced in 2009 when features writer Dan Evans got caught in the act listening in on the voicemails of Miller's former stepmother Kelly Hoppen.
Then in 2011, the newspaper was shut down by Rupert Murdoch in the wake of public outrage that missing schoolgirl Milly Dowler's phone was hacked, which happened before Wallis's time as deputy.
Since its closure, a total of eight journalists, including Coulson, have been convicted of being part of the hacking the hacking plot.
Wallis's trial had heard how in the summer of 2004, the NoW broke the news of Blunkett's affair with a married woman – referred to at the newspaper by the codenames Noddy and Big Ears.
At the time, Wallis was on holiday in France but telephone exchanges with his boss suggested he "must have been involved" too, said prosecutor Julian Christopher QC.
In July 2005, the NoW broke a story about Miller's alleged fling with her Layer Cake co-star Craig after Evans picked up her message to him saying "Hi, it's me. I can't speak, I'm at the Groucho with Jude. I love you".
After hearing the message, Wallis told him "You're a company man now", Evans had claimed.
In April 2006, Goodman wrote a story about then-Prince William's "drunken conduct" based on a hacked message from Sandhurst commandant Major General Andrew Ritchie to royal aide Jamie Lowther-Pinkerton.
The court heard that Wallis emailed Goodman about the story, asking: "Remind me how we know this to be true."
But in his defence, Wallis denied being involved in the hacking plot, saying he was not concerned with the details of the sources of big stories after they had already been vetted by company lawyers.
He told the jury that at the time Blunkett's affair with a married woman was exposed through phone-hacking, his boss Coulson had misled him into believing the information had come from a well-placed source.
He also highlighted his work on the newspaper's behalf drawing up amendments to the Press Complaints Commission editors' code of practice.
After the verdict Wallis tweeted: "Thanks so so much to all those who stood by me – so grateful #StillStanding."
Speaking outside court, Wallis said: "Four years. Four years after I was arrested, I finally walk out of here a free man. It's cost me and my family most of our life savings.
"It's ruined my life all because of a vicious politically-driven campaign against the press launched by (former Director of Public Prosecutions) Keir Starmer and (his then principal legal adviser) Alison Levitt.
"This is the culmination of a political drive by the police and the CPS. It's a disgrace."
Wallis went on to thank his legal team, before adding: "I just want to say I will never get over this. I've been virtually unable to work for four years.
"It's taken my health, my family's health and all because of a campaign against journalists."
Asked by a broadcaster if he blamed Coulson for landing him in the dock, he replied: "I believe the people who got me into this situation were the CPS and Operation Weeting detectives who when I was arrested talked to me about Milly Dowler – basic detective research would have shown I was not even working."
Wallis left with his legal team saying he was "going off to have a drink".
Reacting to the not guilty verdict, Scotland Yard said it carried out its investigation "without fear or favour".
In a statement, it said: "It was only right that the Metropolitan Police Service carried out a full and thorough investigation to establish if crime had been committed and to hold to account anyone responsible. The victims deserved no less.
"This was a challenging and complex investigation during which we have been highly conscious of the sensitivities and legal complexities. We have carried out that investigation without fear or favour.
"All the evidence has been aired publicly in a court of law and the jury have made their decision. That is a decision we respect."
Former News of the World features editor Jules Stenson, 49, from Battersea, south-west London, is the last of the eight NoW journalists to be convicted of being part of the hacking plot. He pleaded guilty in December last year and will be sentenced at the Old Bailey on a date to be fixed.
Former Daily Mirror editor Piers Morgan Tweeted: "Thrilled for @neilwallis1. One of the best journalists I've worked with. A good man who's been through 4yrs of hell."