Weary readers will have to forgive me for returning, yet again, to the thorny topic of our recent interview with Denzel Washington. When I met Washington in London last month, it was not my intention for the original article to spawn a series of tawdry sequels, a full-on trashy franchise. But sometimes the plot moves on and demands resolution.

This is what happened. At one stage during the interview, discussing his time in Hollywood, Washington remarked that, for whatever reason, "he never befriended any white actors". My own view was that he was simply being candid, describing his experience as a young black actor in a predominantly white industry. But last week one of Washington's representatives (or someone purporting to be) stepped in to clarify his statement to Yahoo! News. "I sat in on this interview," the rep said. "The part they fail to mention is that after he said 'never befriended any white actors' he mentioned 'except' and then listed Tom Hanks, Mel Gibson, Julia Roberts etc. They cut the rest of the thought out."

Yahoo! ran the story, though it did not name the rep. The story was then picked up and disseminated to millions more readers via a number of other news and gossip sites, including Us magazine and Perez Hilton, all of which ran the representative's version as fact. Hilton went on to accuse me of "some shady-ass journalism!!"

There was just one problem: the story was demonstrably untrue. I listened back to the audio file (you can do so yourself here). Washington did not say what the representative quoted him as saying. And, even if he had, how could they have known? There had been no publicist sitting in on the interview last month.

If you're going to accuse someone of telling lies, it's probably best to lay your cards on the table. On Tuesday I wrote a follow-up piece explaining that yes, I had streamlined Washington's original statement. I had removed the umms and the aaahs, his slight hesitations and my annoying interjections. But I stood by the article. I do not think it misrepresented what he said, or ignored any crucial clarifying remark that followed. I am not in the habit of doing that; nor have I ever been accused of doing so in the past. Perez Hilton is right – that would be shady-ass journalism.

Enough with the backstory. Yesterday, in response to our inquiries, we received a number of emails. One of these came from a spokesperson at Yahoo!, which ran the original story. Yahoo! insisted that the disputed quote had come from a "credible source" and that the organisation therefore was prepared to stand by it. Another, crucially, came from Washington's personal publicist at the William Morris agency in Los Angeles. It revealed that the quote had not originated from his office. In other words, the spokesperson credited as "one of Denzel Washington's public relations representatives" was not Denzel Washington's public relations representative at all.

For good measure, Washington's publicist pointed out that the original Guardian interview was not a concern. "We did not give a quote to Yahoo! on this matter," he went on to explain, "and see no reason for any further conversation relating to it."

In a brief, follow-up mail, the publicist added that "this is a non-issue for us". That shows admirable restraint and tolerance on his part. His office now appears to have been the victim of a fraudster, passing him-or-herself off as "Denzel Washington's rep" and furnishing the US news media with made-up quotes from his client. If that was me, I'd be hopping mad.

As it is, we shall probably never know the identity of the rogue impostor. But it feels good to have them confirmed as a fake (by Washington's press representative, if not yet Yahoo!).

The whole experience has given us a fascinating insight into the misty machinations of celebrity journalism. It shows how a bogus story (when not properly verified) can spread like wildfire across the internet, casually traducing the reputation of a writer and a newspaper as it goes. And once the story is out there, it's extremely hard to douse it down; let alone find out who lit the match.

Let me wrap this up with a clarification of my own. I have no particular beef with the numerous news organisations that presumably printed the lies in good faith (though prior verification would have been good journalistic practice). Neither do I have any gripe against Washington's (genuine) press representatives, who work hard for their client and who handled the original interview with the utmost courtesy and professionalism.

And nor, most crucially, do we have any issue with Washington himself. The actor struck me as a thoroughly honest, decent and good-hearted individual. Denzel Washington does not need people stepping in to put words in his mouth and "explain" what he meant. No doubt he would be horrified to learn there was some self-appointed guardian, hellbent on shielding him from a controversy that did not even exist to begin with.

This, in fact, is the one person I have a problem with. I reserve my irritation for the bungling fraud who cooked up fake quotes and wound up spinning a non-issue into a full-blown falsehood. We may never be able to name the culprit. It is a relief, at last, to expose the falsehood.