A former News of the World reporter whose byline appeared on a story about Kate McCann’s diary on her missing daughter has said he believed the paper had permission from the McCanns to publish the story.

“My understanding was if they didn’t give the green light the story wouldn’t be published,” Daniel Sanderson told the Leveson Inquiry today. “Seeking their permission was not in my sphere of responsibility,” he said, adding that he believed the then news editor, Ian Edmonson, had been in touch with the McCanns’ press secretary “on a daily basis.”

Testifying at the Inquiry last month, Kate McCann, mother of missing toddler Madeleine, said the News of the World’s publication of her diaries was done without her knowledge, leaving her feeling “totally violated”.

Sanderson said it was “wrong” to for the paper to publish the diaries without the McCanns’ consent, adding that he had “every intention” of apologising to the family.

He described how the diary had been “publically circulated” around Portugal, and said he had contacted a Portuguese journalist who he was told was in possession of it before liaising with Edmonson. He said he was unaware at the time that the ultimate source of the diary was the Portuguese police, who had obtained it when the McCanns’ holiday home in Praia da Luz was investigated following Madeleine’s disappearance in May 2007.

Lord Justice Leveson pressed Sanderson about the provenance of the diary, with Sanderson repeating that his understanding was publication would not go ahead without the express permission of the McCanns. He conceded that the diary was “clearly a private document” and that the “whole thing caused me concern”, adding that his writing had been taken out of the final copy, leaving the diary printed in its entirety.

He went on to describe the “high-pressure” environment of the tabloid, saying that “you have to give a certain part of your life over” to the paper in order to work there. He denied, however, that there was a culture of bullying at the redtop.

Also testifying today was private investigator Derek Webb, who was hired by the tabloid this year to monitor lawyers Mark Lewis and Charlotte Harris, who both acted for phone hacking victims. A former police detective, Webb revealed he had surveyed around 150 different people at the instruction of the News of the World between 2003 and 2011, including Labour MP Tom Watson and, on one occasion, Jude Law and Sienna Miller.

He told the Inquiry how he had met with former chief reporter Neville Thurlbeck around 1999 or 2000, with Thurlbeck telling him there may be surveillance work for him at the paper after his retirement. When he retired in 2003, Webb said he soon began working “full-time” for the paper, being asked by the newsdesk to follow an individual or go to a particular address.

Contrary to former editor Colin Myler’s testimony that the use of PIs was cracked down upon once he joined the paper in 2007 in the wake of the phone hacking scandal, Webb said he was carrying out the “same type of work” as he had during Andy Coulson’s reign.

He revealed it was Thurlbeck who had told him in 2009 that there had been a “hiccup” with the use of PIs after the jailing of Clive Goodman and Glenn Mulcaire, and urged Webb to terminate his private investigator’s licence and join the National Union of Journalists. He was also asked to change his email address from Silent Shadow — referring to the name he had been trading under — to Derek Webb Media. It was revealed yesterday that Webb was still referred to as “silent shadow” in a July 2009 email sent by then managing editor Stuart Kuttner, although the company Silent Shadow had gone out of business at the time of Webb’s 2007 arrest.

Webb said he would not have described himself as a journalist — despite the paper’s legal chief Tom Crone being under the impression he was — noting that his main work was “surveillance”. He estimated watching MPs and celebrities made up 85 per cent of his job, with the remaining 15 per cent being drugs offences and crime.

The Inquiry continues on Monday.

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