Paul Smith contacted the PCC after articles appeared in the Hull Daily Mail on 4 March this year headlined "Town website publisher's porn business", "The sickening porn behind this man's veil of respectability" and "Town website: the sordid truth".

The articles reported the complainant, who published a local community website promoted by the local council, had designed thousands of hardcore porn websites - claiming he owned the domain names to almost 4,000 sites.

Mr Smith said this was incorrect because he had only ever designed a hundred or so websites, including some adult sites, and had bought just over 100 domain names, nearly half of which were dormant.

He complained the articles had breached the Editors' Code of Practice for accuracy, privacy and the use of clandestine devices and subterfuge – but only one of his concerns about accuracy was upheld.

The newspaper argued at the time of its investigation, a web registration search showed the complainant owned 3,991 domains, the majority of which were adult ones.

But it was not able to prove this figure conclusively after publication.

The Commission said these were crucial allegations which the newspaper should have been able to substantiate fully, saying readers would have been misled about the scale of Mr Smith's involvement in adult websites.

The complainant was also concerned a journalist from the newspaper had misrepresented her identity when first contacting him, including creating a bogus Facebook page.

She aimed to find out if he would create a website for an escort girl but revealed her true identity when meeting him in person.

The PCC ruled the newspaper's public interest defence was justified on this occasion and the level of intrusion was not of a particularly serious order.

It said the newspaper "could legitimately claim this method was necessary to obtain the information, believing that the complainant may not have been forthcoming to a direct journalistic approach about his willingness to consider designing a website for an escort".

Other complaints on privacy and accuracy relating to the articles were also not upheld.