London (CNN) -- Four current and former employees of Britain's Sun newspaper were arrested by authorities investigating claims of inappropriate payments to police, News Corp. and police said Saturday.
Police searched the men's homes as well as the East London offices of News International, the News Corp. subsidiary that publishes the Sun and other U.K. newspapers, London's Metropolitan Police Service said.
A 29-year-old police officer was also arrested Saturday at the central London police station where he works, police said, on suspicion of corruption, misconduct in a public office and conspiracy in relation to both offenses. He works for the force's Territorial Policing command.
Three of the men were arrested at their homes -- two of them, aged 49 and 57, in the county of Essex, and one aged 48 in London. A fourth, aged 42, was arrested at an east London police station.
By late Saturday, police said that all five men were subsequently released after posting bail. The current and past newspaper employees were all set to "return pending further inquiries" in April or May, according to the Scotland Yard statement.
Earlier, they'd been questioned on suspicion of corruption, aiding and abetting misconduct in a public office, and conspiracy in relation to those offenses.
The operation "relates to suspected payments to police officers and is not about seeking journalists to reveal confidential sources in relation to information that has been obtained legitimately," an earlier police statement said.
News Corp. said it is cooperating with the search of its News International offices.
Police said the operation was the result of information provided to police by News Corporation's Management and Standards Committee (MSC), which was set up to look into conduct at News International, a subsidiary of News Corp.
The News Corp. statement said the company had "made a commitment last summer that unacceptable news gathering practices by individuals in the past would not be repeated."
The committee was asked "to proactively co-operate with law enforcement and other authorities if potentially relevant information arose at those titles. As a result of that review, which is ongoing, the MSC provided information to the Elveden investigation which led to today's arrests."
The Sun, which is Britain's best-selling tabloid newspaper, was the sister paper of News International's now-defunct Sunday title, the News of the World.
A spokeswoman for News International earlier declined to comment on the search of its offices.
The investigation into alleged corruption, known as Operation Elveden, is being run in conjunction with an inquiry into phone hacking prompted by allegations of wrongdoing at News of the World.
The best-selling News of the World tabloid was shuttered in July amid outrage over claims that its staff hacked the voicemail of a missing 13-year-old girl who turned out to have been murdered.
James Murdoch, chief executive of News International and the son of media mogul Rupert Murdoch, has insisted that the practice of phone hacking was not widespread.
News Group Newspapers, a subsidiary of News International that was the publisher of News of the World, agreed to payouts in the High Court totaling hundreds of thousands of dollars earlier this month over phone hacking claims.
Among those who read statements in court were Labour Party lawmaker Chris Bryant, former Deputy Prime Minister John Prescott, actor Jude Law, the actor's ex-wife Sadie Frost, and high-profile rugby player Gavin Henson.
News International said the company "made no admission as part of these settlements that directors or senior employees knew about the wrongdoing by NGN or sought to conceal it. However, for the purpose of reaching these settlements only, NGN agreed that the damages to be paid to claimants should be assessed as if this was the case."
Both James and Rupert Murdoch, as well as senior executives at News International, have testified before British lawmakers examining allegations of wrongdoing.
A public inquiry has also been set up to look at claims of widespread misconduct by the British media. Representatives of a range of news outlets have appeared before it.
There have been 13 arrests in connection with Operation Elveden and 17 in relation to Operation Weeting, the phone hacking inquiry, the Metropolitan Police confirmed. Three people have been arrested in connection with both investigations.
Operation Elveden is overseen by the British police watchdog, the Independent Police Complaints Commission.