The phone hacking investigation was not reopened because of a "closed mindset in the force", a former Metropolitan Police commissioner has said.Sir Paul Stephenson told the Leveson Inquiry the Met developed a “fixed mindset and a defensive mindset” in 2009, when the original investigation was reviewed by Assistant Commissioner John Yates. He said there was a flawed assumption that the 2006 investigation was satisfactory.He added: “What we didn’t do is go back and challenge the reasons for those decisions in 2006. We didn’t go back and challenge the reasons why it was limited. Had that taken place we might have been in a better place."In so much as it felt like a successful investigation, the fact this did not feel a priority was a relevant factor in terms of using resources. I then go on to think we got ourselves hooked on a defensive strategy that we would not expend significant resources without new evidence.”“That was a perfectly logical situation to be in, provided your assumption about the original success of the operation was correct.”On his written statement to the inquiry Stephenson said Kit Malthouse, chair of the Metropolitan Police Authority, had referred to hacking allegations as driven by a “level of hysteria” created by politicians and the media, and said the force should not be devoting further resources to Operation Weeting.In 2010, London Mayor Boris Johnson said phone hacking allegations had been substantially investigated and accused the Guardian and Labour party of whipping up the scandal to embarrass Andy Coulson, then David Cameron's communications director.The Guardian published the phone hacking allegations in 2009 but Operation Weeting was not launched until January 2011. In his written evidence, Stephenson said he had been reassured by Yates that further investigation into the allegations was not needed.He said: "I continued to have intermittent discussions with AC Yates as the Guardian maintained its coverage on this issue. I continued to be reassured by him that there was nothing new in the allegations that would warrant the reopening of the investigation.”The statement said a "scoping exercise" had been undertaken by Yates after fresh allegations were printed in the New York Times in 2010, and the Crown Prosecution Service were informed by his team there was “insufficient evidence to mount a prosecution”.Stephenson told the inquiry Yates was the natural officer to conduct a review of phone hacking evidence in 2009 but admitted Yates' friendship with Neil Wallis, former News of the World deputy editor, may have appeared inappropriate in the context.He added: “[The investigation] was not a priority for me as a Commissioner. It remained as one of the many many pieces of noise. I think [Yates] acted in good faith. As far as I was concerned, it was being dealt with adequately.”Stephenson was asked about his own links to Wallis, with whom he had met several times during his time as commissioner. He resigned last year after criticism for the hiring of Wallis as a consultant to the Met’s press office in 2009.He told the inquiry he was not aware Wallis was a person of interest in the investigation until April 2011 and said he regretted entering into a contract with the former News of the World employee. He said it would have been “clumsy” to meet with Wallis after his name was associated with hacking.He added: “I realised it was off a different order, I would have been much more circumspect with meeting News International.”The former commissioner had also come under fire for an extended stay at Champneys in Hertfordshire following an operation, after it was revealed the public relations company run by Wallis had been hired by the luxury brand two months before his visit. He maintains he was not aware of the connection before or during his recovery at the spa.Stephenson’s hospitality register, shown to the inquiry, recorded a significant number of meetings with national newspaper editors and journalists during his time as commissioner, including a 2009 dinner with Yates, Wallis and the Met’s head of press Dick Fedorcio. He said he sometimes personally paid for drinks with press as he was uncomfortable with the idea of billing the public purse for alcohol.He added: “I would say for every journalist I've ever met they would be delighted if I was indiscreet. My job was to ensure I wasn't.”