London (CNN) -- Four top British police officers will not face further police investigation in connection with an inquiry into phone hacking by journalists, the Independent Police Complaints Commission said Wednesday.
They are former Metropolitan Police Commissioner Paul Stephenson, former Assistant Commissioners John Yates and Andy Hayman and former Deputy Assistant Commissioner Peter Clarke.
Stephenson resigned as head of London's Metropolitan Police, also known as Scotland Yard, after it was revealed that Scotland Yard had hired a former top News of the World journalist to be a communications consultant. The revelation came the same day police arrested the journalist, Neil Wallis, over the phone-hacking investigation.
Stephenson insisted he had done nothing wrong.
All four officers were referred to the IPCC by the local police authority after their involvement in the phone-hacking scandal engulfing News of the World and its parent company, News International, came under scrutiny.
News of the World was shut down last month amid allegations its staff had hacked the voice mail of people ranging from celebrities to crime victims, and bribed police. Top Metropolitan Police officers were accused of being too cozy with senior News International staff.
The IPCC said in a statement that "in relation to their alleged respective roles in the 'phone hacking' investigation, the conduct of none of these officers amounts to recordable conduct."
IPCC Deputy Chair Deborah Glass said the Metropolitan Police had "rightly come under huge scrutiny" over its role in responding to allegations of phone hacking by News of the World, Britain's best-selling Sunday paper.
"There can be no doubt about the damaging effect of the perceived inadequate response -- in particular, the failure to notify its many apparent victims -- on public confidence. Sir Paul Stephenson and John Yates both acknowledged this in their decisions to resign," she said.
But, she added, a "clear line must be drawn between what is a recordable conduct matter -- in effect, conduct that is either criminal or for which an officer should be disciplined -- and public concerns that will be addressed and scrutinized by Lord Justice Leveson's public inquiry."
The Leveson inquiry was set up by Prime Minister David Cameron to look into the conduct of the UK media and allegations of phone hacking and police corruption.
Stephenson said the outcome of the IPCC probe "is as I would have expected it to be.
"I regret resources have had to be expended on this matter," he said in a statement.
Yates handed in his resignation the day after Stephenson quit. He was the officer who decided in 2009 that there was no need to open a new police investigation into phone hacking, despite the 11,000 pages of evidence sitting at Scotland Yard -- a decision he later admitted to Parliament was "crap."
The IPCC said it "would agree that he made a poor decision in 2009" but said it saw no purpose in questioning him about it again.
However, Yates faces further investigation over his alleged role in securing a police job for Wallis' daughter, the IPCC said.
Yates said he was pleased he would not be scrutinized further over phone hacking but "disappointed" he still faced questions over what he called his "peripheral involvement" in the employment of Wallis' daughter.
"I strongly deny any wrongdoing and I am completely confident that I will be exonerated," he said in a statement.
Cameron has faced questions over his judgment in hiring former News of the World editor Andy Coulson as his communications adviser after he resigned from the newspaper. Coulson says he was not aware of wrongdoing while he edited the paper.
In a statement released Wednesday by the prime minister's Downing Street office, Cameron said: "Clearly if I had known then all the things I know now, then obviously I would have taken different decisions."
The IPCC's decision comes a day after a parliamentary committee examining the phone-hacking allegations at News of the World released dozens of documents related to its inquiry, reigniting questions over whether News International had tried to cover up what happened.
Among the documents was a 2007 letter from the paper's former royal correspondent Clive Goodman -- who was sacked and jailed over intercepting royal voice mail -- to News International executives, in which he says that phone hacking was "widely discussed" at the newspaper until explicit reference to it was "banned by the Editor." The editor at the time was Coulson.
A number of senior News International figures have been asked to give evidence to Parliament's Culture, Media and Sport Committee in September. Coulson and others have also been sent letters asking if they wish to add to or amend their previous testimony before the panel.
CNN's Carol Jordan contributed to this report.