A former police officer told the Leveson Inquiry today that his bosses at the Information Commissioner’s Office warned him the press was “too big” to take on over private investigators.

Alec Owens, who was a senior investigator in Operation Motorman, an ICO-led investigation into allegations of data protection offences by the British media, revealed he had found notebooks in private investigator Steve Whittamore’s home with 17,500 entries identifying each reporter and newspaper who had commissioned a task. The “Pandora’s box” of information also included invoices to and payments from newspapers, criminal record checks, car registration checks and ex-directory telephone numbers.

Owens said, “we could identify the newspaper, the journalist, Whittamore, who he used, the blaggers, the corrupt people, and we had a paper chain right the way up and down.”

However, a “shocked” Francis Aldhouse, the then deputy information commissioner, told Owens the press were “too big” to take on.

Owens said that no journalists had been questioned or charged in Operation Motorman, adding, “I wish we had the opportunity to look at all this.” He contended that the evidence found was “strong enough to stand on its own” to prosecute journalists, noting that some were using Whittamore 300 or 400 times.

Owens also revealed that the mobile phone number of abducted schoolgirl Milly Dowler and her family’s ex-directory telephone number were featured in Whittamore’s notebooks, as well as the names of other victims of phone hacking at the News of the World.

Operation Motorman, carried out in 2003, investigated the use of a private investigators by the media to obtain personal information. In 2004, Whittamore was arrested and given a conditional discharge. In September of this year, Owens gave a disk of his files on the operation to the Independent newspaper, revealing previously unpublished details of the scale of the press use of private investigators. Just weeks before coming to the Inquiry, Owens’s home was raided under a warrant by Cheshire police, in an operation he described as a “fishing trip.”

Earlier in the day, former Number 10 director of communications Alastair Campbell called for media reform, labelling the British press “putrid”.

In his three-hour testimony, Campbell described a “culture of negativity”, with the Daily Mail being the most “relentless” for its crime and health scares. He said parents whose children have had measles should blame negative coverage over the MMR vaccine, and cited social workers as only ever being defined negatively in the tabloids, which he said impacted on recruitment, morale and the services they provide. He said the press’s treatment of the Dowlers and McCanns was “not atypical” but rather something that happened to anyone who became a “news commodity”.

He went on to say the paper was “utterly the product of one person”, and questioned editor Paul Dacre’s assertion that he had never published a story based on illegal information. Campbell argued that editors may genuinely not know “that the law is being broken left, right and centre”.

Of journalists, he said, “they are the spin doctors. They are the ones deciding what the line is…The line then gets reported as public opinion.”

While stopping short of accusing the Mail of phone hacking, Campbell said he was “unprepared” to say the paper had “never done anything untoward”.

He said that during his time at Downing Street he was “very concerned” about how many stories about Cherie Blair and her life coach Carole Caplin were getting out to different parts of the press. While admitting he had no evidence of hacking, Campbell said in his witness statement that it was “at least possible” that this is how stories were revealed.

Campbell claimed that those who argued loudest for freedom of the press were “terrified” of regulation, but that the majority of journalists had nothing to fear. Those who were terrified, he said, were scared of losing “the ability to do this sort of journalism they have been doing over the last decade or so.”

He agreed with Guardian journalist Nick Davies that a public interest advisory body should be introduced to help guide reporters. He also argued in favour of a new regulatory body that would not have current media representatives sitting on it. He advocated a US-style system of fact-checking on newspapers as well as league tables to see which papers adhered to the code of practice.

Also speaking today was Mark Lewis, a solicitor for victims of phone hacking. He described the surveillance carried out on him and his family by News of the World private investigators as “truly horrific.” In an impassioned testimony, he went on to say that News International sought to “destroy” his life and “very nearly succeeded”.

Lewis also refuted claims in a dossier compiled by NI lawyers that he had leaked information to the Guardian, accusing solicitor Julian Pike and News of the World lawyer Tom Crone of “complete arrogance and idiocy”.

The hearing continues on Monday, when we will hear from Francis Aldhouse, the former ICO investigator on Operation Motorman, solicitor Charlotte Harris and author Peter Burden.

Follow Index on Censorship’s coverage of the Leveson Inquiry on Twitter – @IndexLeveson.