In 2009, the Times "outed" an anonymous blogger. It was a strange exercise at the time. A "quality" newspaper devoted its resources to forcing into the public domain the identity of the author of the popular and extremely well-written police blog known as "NightJack". As Paul Waugh and others noted as it happened, it was somewhat weird and unfortunate that a newspaper which should respect anonymity as a condition for providing useful information was exposing an anonymous writer providing useful information.

Not only did the Times seek to expose the blogger, they even went to the High Court to defend an attempt by the blogger to protect his anonymity. In a detailed witness statement of 56 paragraphs and with 56 pages of exhibits, the journalist purported to show how by using considerable investigative skill and amazing detective work he was able to use minute details over several blogposts to piece together the identity of the blogger. Anyone reading this remarkable witness statement gets a sense that the journalist not only deserved his scoop, he also probably deserved a Pulitzer.

This witness statement (which I possess, but will not publish as it contains personal information about the blogger and his family) was impressive enough to change the course of the court case. As the case report states clearly at paragraph 3:

It was asserted in the Claimant's skeleton [argument - the summary of the claim] for the hearing of 28 May that his identity had been disclosed to The Times in breach of confidence. By the time the matter came before me, on the other hand, Mr Tomlinson [the blogger's barrister] was prepared to proceed on the basis that the evidence relied upon from Mr Patrick Foster, the relevant journalist, was correct; that is to say, that he had been able to arrive at the identification by a process of deduction and detective work, mainly using information available on the Internet.

The concession by the blogger's barrister was in my view determinative of the case. If there was no breach of confidence -- or no wrongful act of any kind in obtaining the information -- then there was really no inherent privacy which the blogger to assert. There was no need therefore for the judge Sir David Eady to see whether the interference with the privacy right was proportionate or lawful; there was no privacy right to begin with. And, as Eady said, blogging is essentially a public activity.

However, witness statements and exhibits do not come about easily. There is considerable input by lawyers. The decision to fight the case would also not have been made by the journalist in question, but by his senior managers. High Court litigation is uncertain and expensive. The decision to fight the case would not have been made lightly. And key to the advice given to senior managers and the decision they made would have been that witness statement. It would have been their decision to put this evidence before a High Court judge, and not that of the journalist.

The decision looked like it paid off. They won, and the Times duly ran the exclusive. Times columnists assured us ponderously that something rather splendid had been done in the public interest. And, in the meantime, the blogger pulled his blog and faced disciplinary action from his employer. The loss of the blog was particularly unfortunate, as it robbed the public of a brilliant insight into the daily lives of police officers written by perhaps the best writer the blogging medium has ever produced.

In my view, there was always something not quite right about what the Times did. The explanation offered smacked to me of being retrospectively compiled and reverse engineered, as if someone had solved a maze by starting at the centre and then worked outwards. I do not know if this was or was not the case. Soon it was clear that these doubts were shared. Just as "everyone" in Fleet Street knew that there was something not quite right about Johann Hari's journalism or the tabloids' use of mobile telephony, it was widely held that something about the exposure of NightJack did not stack up.

But even when it became known that the journalist in question had been disciplined as an undergraduate for hacking into his university computer network (but was still hired by News International anyway), that could not take anything away from the evidence sworn and put before the High Court. The managers and lawyers at Times Newspapers Limited has confidently assured the High Court that their young reporter had single-handedly pulled a journalistic feat comparable to what took over a hundred commenters at Jack of Kent to do for "David Rose".

And so nothing happened, until last week.

Lord Justice Leveson's inquiry team sent out questionnaires to all the newspapers. One of the standard questions was about computer hacking. This clearly caused a bit of an issue for the Times. Over four witness statements the Times admitted the following facts: that there had been a computer hacking incident in 2009 by a male reporter; the computer hacking was in the form of unauthorised access to an email account; a disciplinary process had been commenced after concerns from the newsroom; the reporter admitted the unauthorised access during that disciplinary process; it was held that there was no public interest in the attempted hacking; the incident was held to be "professional misconduct" and the reporter was disciplined; and the reporter is no longer with the business having been dismissed on an unrelated matter.

What was most striking about all this was the date: 2009. Was it possible that the computer hacking was in respect of the exposure of NightJack? This would be a serious matter, for not only would it raise issues under the Computer Misuse Act, it may be that there had been perjury in the case at the High Court. Had computer hacking been admitted to the court then there would have been little doubt that it would have affected the outcome of the case.

So a careful process was commenced. I blogged here yesterday putting together what the witness statements told us whist Paul Waugh at Politics Home made connections between the new evidence and the NightJack case, about which he had previously written. Tom Watson MP, the blogger Old Holborn, and others, asked questions on Twitter. But what was missing was a firm connection: there was no direct link between the new evidence and the NightJack case. It may not have been the same journalist, and it may not have had anything to do with a published story. I sent an email query to the Times (it remains unanswered).

And then, last night, the Guardian stated that the 2009 incident was in respect of NightJack. So, instead of answering a formal email request or properly disclosing it to the Leveson inquiry, a "source" leaked it to David Leigh of the Guardian. This was an odd move, not least because the journalist in question now writes regularly for the Guardian on media matters. (Yes, that irony is indeed correct: the Guardian uses a media correspondent with a record of computer hacking.)

One cannot be certain that the Guardian is correct without further evidence or an open admission. But if it is right, then this opens up some extremely serious questions for the Times. At some point in 2009 the internal managers and lawyers at the Times became aware that the High Court had proceeded on a flawed basis in dealing with the NightJack injunction. This information may have come out before the court hearing or afterwards. They would also have become aware that a major exclusive had been based at least in part on computer hacking. If the Guardian revelation is sound, then it would appear that the Times needs to explain who knew what and when, and why nothing has been done about it until Lord Justice Leveson's questionnaire.

In all this, one should not blame the journalist too much (and you may notice he has not been named in this post other than in the quotation from the case report). He did what one suspects many young and ambitious journalists would do if they could get away with it. The real failure here would appear to be -- as with Hari at the Independent -- one made by managers at the Times, and perhaps those who advise them. If the Times did throw its financial and legal might behind a story which they knew to be based on computer hacking and did not inform the court -- or found out later, and still told no one about it -- then that, in my view, would be a scandal perhaps comparable to the tabloids' abuse of phone hacking.

David Allen Green is legal correspondent of the New Statesman and writer of the Jack of Kent blog