The Sun’s Tom Wells, Neil Millard and Brandon Malinsky and former Daily Mirror reporter Graham Brough were found not guilty of conspiring to commit misconduct in a public office, bringing the total number of reporters to be cleared by a jury to 14.
The jury reached not guilty verdicts on all but one count against Wells and former Serco immigration detention centre official Mark Blake.
The Common Serjeant of London discharged the jury and gave the Crown seven days to decide whether to reach a re-trial.
The verdicts came as the Crown Prosecution Service carries out an urgent review of all the remaining cases brought following the £20 million Operation Elveden police probe in to newspapers’ dealings with public officials.
So far, just two journalists have been found guilty and the Court of Appeal quashed the conviction of the first - a News of the World reporter - and gave the second leave to appeal.
In all, 27 journalists have been charged under Operation Elveden and there are 12 awaiting trial or retrial later this year.
After leaving court, Malinsky said the police should stop “persecuting innocent journalists” in cases which were “a disgraceful waste of public money”.
He added: “I’ve had nearly two years of torture.
“They should be out on the streets stopping real crimes instead of this disgraceful witch hunt. It’s an ordeal that should never have happened.”
Brough said: “I hope these acquittals will remove the fear currently freezing investigative journalism which is the lifeblood of any democracy. I am greatly relieved that professional reporters have not been criminalised today.”
The jury could not decide on a charge relating to Wells’ dealings with Blake who, while working at Colnbrook secure immigration removal centre, allegedly pocketed nearly £8,000 in exchange for tips.
But he was cleared of wrongdoing in relation to two prison officers who allegedly sold information about James Bulger killer Jon Venables while he was behind bars in 2010 and 2011.
As he walked away from court, Wells told reporters: “There is a lot I would like to say, but I can’t say anything.”
All the defendants denied various counts of conspiring to commit misconduct in a public office, while Blake additionally denied misconduct in a public office.