Mr Wallis said he helped Lord Stevens “throughout” his successful application to become head of the Metropolitan Police, telling him to stress he was a “copper’s copper” or “thief-taker”.
The former tabloid executive also offered his opinions on what the post required to Sir Paul Stephenson, who took over as Met commissioner in 2009.
Three senior figures at Scotland Yard have resigned over their links to Mr Wallis, who has been arrested on suspicion of phone hacking.
Sir Paul and assistant commissioner John Yates stood down last July, and the force’s communications chief Dick Fedorcio quit last week. They all faced criticism over the decision to hire Mr Wallis to provide PR advice for Scotland Yard on a £24,000 contract from October 2009 to September 2010.
Mr Wallis, who was executive editor of the now defunct News of the World, told the inquiry yesterday that Mr Fedorcio introduced him to Lord Stevens in about 1998. He said he aided the senior officer when he sought to become the head of Britain’s largest police force.
Mr Wallis said in a written statement: “I advised Lord Stevens throughout the application and interview process.
“I recall having a number of discussions with him.
“My input in this process was that he would be well advised to emphasise that he was a ‘copper’s copper’ or ‘thief-taker’ – in other words, he was a man of action, rather than rhetoric.”
Mr Wallis said Lord Stevens, who was commissioner from 2000 to 2005, discussed only issues of policy and presentation with him, and never mentioned operational policing matters.