See if you can join the dots. A mystery web user has been editing a select group of entries on Wikipedia. This person – or could there be more than one? – works in Clerkenwell in London, always using the same computer, identifiable by its IP.

The Earl of Derby, the co-founder of the Carphone Warehouse, David Ross, the Saad Group, a Saudi Arabian conglomerate, and its billionaire founder Maan al-Sanea are among his or her (or their?) targets.

The same computer has also been used three times to edit the Wikipedia entry for Baron Black of Brentwood, the executive director of the Telegraph Group, otherwise known as Guy Black, former chief spin doctor for the Conservative Party. And it was used to make a minor amendment to the entry on Mark Bolland, the former aide to the Prince of Wales, to ensure that the name of his company, Bolland and Associates, was entered correctly.

Can you see? There is a common thread that draws together this diverse group. Guy Black and Mark Bolland are civil partners. The other three wealthy individuals are clients of Bolland and Associates, which has its office in Clerkenwell, where the mystery computer is also located.

It has long been an issue for Wikipedia that PR people have been "cleaning up" some of its content to benefit their clients, when the idea of its founders was that it should be written by unpaid contributors with no financial interests to influence their judgements.

Mr Bolland has not replied to an inquiry from The Independent about whether he, or someone in his office, has been up to a bit of Wiki cleansing, so all we know for certain that someone in Clerkenwell is taking a close interest in people in whom Mr Bolland is also interested.

The Clerkenwell scribe started modestly, adding a line in April 2009 to the Wikipedia entry for a private school in Saudi Arabia. Three weeks later, at 9am on a Saturday, he or she was bolder. He called up the entry for David Ross, and deleted the final six lines on his personal life, which recorded that Ross has a son with Michelle Ross, a former lap dancer, and was now dating Emma Pilkington, a 22-year-old he had taken to a party hosted by Prince William on a yacht owned by the Getty family.

When another Wikipedia editor restored the missing material, the mysterious computer user in Clerkenwell deleted it again, this time at 8.12am on a Wednesday, in the first of several cyberspace duels fought with that same computer.

In November 2010, the computer was used three more times to edit the entry on David Ross, until a warning was posted that "in the event of persistent vandalism from this address, efforts may be made to... report abuse". After that, there were no more edits from that computer.

The Earl of Derby has encountered opposition to his plan to build 1,200 homes and a commercial area the size of 13 Tesco superstores on land near Newmarket, in Suffolk. A virtual Who's Who of racing has expressed alarm at the implications for Newmarket's famous race track. The Earl's Wikipedia entry said that the plan had met "considerable" opposition, until the Clerkenwell scribe altered that word to "some". References to Newmarket's potential status as a world heritage site were also deleted.

After other users had gone in and beefed up the section on the controversy, the user from Clerkenwell returned and deleted it altogether, but it took just one minute for another user, styling himself Nunquam Dormio ("I never sleep"), to restore it.

The Wiki entry for the Saad Group was repeatedly modified to remove a paragraph on a terrorist attack in which 22 people died. The entry for the group's billionaire founder, Maan al-Sanea, was doctored to leave in place his "passionate" interest in healthcare and education while deleting a report that his bank accounts had been frozen on the orders of Saudi Arabia's central bank. Out, too, went the downgrading of the group's debt to "junk" and "default" status, together with a reference to a court case. In came a mild, misspelt sentence to say that "it has been reported that the company has recently been hit by the liquidity squeeze effecting [sic] the Middle East".

Opinions vary as to whether it is in order for people working in PR to "cleanse" Wikipedia entries.

"I actually think it's fine to neutralise Wikipedia entries and correct factual inaccuracies but turning someone's entry into pure spin is unacceptable," Mark Flanagan, partner at Portland and a former head of digital at 10 Downing Street, told the magazine PR Week. He added: "It is also vital to respect the rules of Wikipedia and make sure changes are submitted to the community for their approval. Wikipedia is often the top result in search and a key factor in someone's online reputation so I am not at all surprised this has become a hot issue."

Stuart Bruce, managing director of Wolfstar Consultancy, said: "The idea of PR people editing Wikipedia entries has long been extremely controversial. In 2007 Wikipedia founder Jimmy Wales threatened to ban PR agencies from contributing to the site because of a conflict of interest claiming that 'contributors cannot be paid for what they are doing'."

The curious world of reputation management

Lord Black The entry of Lord Black of Brentwood (formerly Guy Black) was modified three times by the 'Wikifixer'. Lord Black is Mark Bolland's civil partner.

The Earl of Derby A client of Mark Bolland, the earl benefited from repeated edits to his Wikipedia entry, playing down the scale of opposition to his development plans in Newmarket.

Maan al-Sanea The billionaire founder of the Saad Group, another Bolland client, found references to the freezing of his bank accounts removed from his Wikipedia entry.

Mark Bolland A Wikipedia entry about the public relations supremo was among those managed by the mysterious 'Wikifixer', adding to speculation that the anonymous editor might have something to do with Bolland himself.