The arrests form part of investigations into illegal payments and phone-hacking that have sparked more than 80 arrests.
Those arrested have included Prime Minister David Cameron's ex-media chief, Andy Coulson, and Rebekah Brooks, the former head of News International, the British newspaper arm of billionaire Murdoch's News Corp media empire.
Facing a public backlash over the allegations, including the hacking of the phones of crime victims by journalists, Murdoch closed one of his tabloid newspapers, the News of the World, in July 2011.
On Wednesday, a 39-year-old officer with Wiltshire police in south-west England was arrested at his home on suspicion of misconduct in a public office, a statement by police said.
A 51-year-old journalist was held in the city of Bristol and another one, aged 32, was picked up in London, both on suspicion of conspiracy to corrupt and conspiracy to cause misconduct in a public office, it said.
The two journalists work for the Sun, a News International spokesperson said.
Police said the arrests stemmed from information provided by News Corp's internal management standards committee, which was set up in the wake of the phone-hacking scandal, which erupted last year.
Along with the main probe into allegations of phone-hacking by journalists, there is a corruption investigation and a separate inquiry into illegal breaches of privacy including computer hacking.
Investigations initially focused into allegations that reporters at News of the World had hacked into voicemail messages left on the mobile phones of celebrities, politicians and crime victims.
Those arrested include a number of former News of the World staff charged with conspiring to hack phones. – Reuters