Paper's editor tells Leveson inquiry that regulator was not proactive enough in preventing excesses in press coverage

Gerry and Kate McCann received £550,000 in a 2008 libel payout from Express Newspapers. Photograph: Lefteris Pitarakis/AP

The editor of the Daily Express has justified its decision to quit the Press Complaints Commission by complaining that the press body failed to stop owner Richard Desmond's papers publishing more than 100 seriously defamatory stories about Madeleine McCann and her parents.

Hugh Whittow said that he was not party to the decision to quit the PCC in January 2011, which was taken by the board, nor was he part of the discussion beforehand as he was not made editor until the following month.

However, he said he agreed with Desmond, the Express Newspapers proprietor, because the PCC was not proactive enough on the McCann story, which cost the newspaper group £550,000 in a 2008 libel payout. All four Express Newspapers titles, including the Daily Express, also printed front-page apologies.

"I did go along with it," Whittow said of the decision to quit the PCC. "I don't think it was serving our best interests at the time because of the McCanns – that was a big story for us and I felt that they should have interevened. Everyone [newspapers] had too much leeway, there was nobody intervening at all as a result."

Inquiry counsel Robert Jay QC asked Whittow whether he was "seriously" putting this forward as a reason for leaving the PCC.

"[These articles] were grossly defamatory, you end up paying £550,000 and you blame the PCC ... Have you got any better reasons for leaving the PCC?" he asked.

Express Newspapers, which also publishes the Daily Star, were forced to settle with the McCanns in March 2008 when they were unable to defend stories which including claims that "Maddy's body sold by hard-up McCanns", admitting in its apology to publishing more than 100 "seriously defamatory" articles.

Gerry McCann told the inquiry in November this was nothing "short of disgusting". Kate McCann told Leveson that the same paper accused the family of storing her body in a freezer. Another story claimed that there was DNA evidence showing the missing girl's body had been put in the boot of the McCann's hire car in Portugal.

The McCanns told the inquiry they had had a conversation with Sir Christopher Meyer, the then chairman of the PCC, who advised them to sue for libel, so they did not make an official complaint to the regulator.

Dawn Neesom, the editor of the Daily Star, admitted to the inquiry that she could not verify the sources of the false McCann stories the paper published, which she said came from the Portuguese police and reporters there. "It was very hard to check sometimes," she added.

Jay asked whether it was normal for stories to be "fed" to her paper and then get published without independent verification.

"It was a risk and to this day I regret that happened in the McCann case, I can only repeat the apology which was published on page one ... for the hurt and distress we caused," Neesom replied.