Ian Burrell: Latest revelations will have MPs scenting blood

Just how damaging is this letter written by the News of the World's former royal editor Clive Goodman in 2 March 2007? It is a dangerous weapon – now that it is in the hands of detectives and some very unhappy members of the House of Commons Culture Media and Sport Committee, who feel they have been led on a wild goose chase by executives at News International.

In his letter, Goodman challenged his dismissal by alleging that his actions were conducted "with the full knowledge and support" of senior figures at News International and that other members of the NOTW staff actively partook in phone hacking.

We now know that the recipients of the letter – NI's executive chairman Les Hinton, the company's human resources chief, Daniel Cloke, and the the managing editor Stuart Kuttner – were fully aware of these explosive claims more than a year before NI made its out-of-court settlement with the hacking victim Gordon Taylor.

The executives were informed that the practice of hacking "was widely discussed in the daily editorial conference" until "explicit reference to it was banned" by the NOTW's then-editor, Andy Coulson. Ominously, when Goodman was asked to attend an appeal hearing against his dismissal he demanded copies of emails, phone records, payment details and transcripts on a scale that hinted at the potential for future investigations into hacking.

So what did NI do? Other documentation published yesterday refers to the investigation by the law firm Harbottle & Lewis of some NI emails. The search found no evidence to support Goodman's claims. Cloke, according to written evidence from the former NOTW editor Colin Myler, published yesterday, was delighted. "Good news," he said. "There is no smoking gun or silver bullet in the emails."

But would such a search ever have found a gun? In another of yesterday's letters, the senior NI lawyer Jon Chapman described the Harbottle & Lewis review as "limited in its scope". He accused NI of overstating its importance. Crone meanwhile aimed his fire at James Murdoch, whose evidence to MPs he flatly contradicted.

NI might dismiss Goodman's smoking gun on the grounds it bears the fingerprints of a bitter former employee. Even so, its four-year-old contents are shocking in the face of those long years of NI denial. And, emerging on a day when so many former NI staff were settling scores, what we were seeing was not so much a single smouldering weapon as a circular firing squad.