Leading article: The case for a wider hacking inquiry is now unanswerable

Was Scotland Yard really taking these allegations seriously before this week?

The Metropolitan Police's handling of the phone hacking scandal has been suspicious from the very beginning. For a long time, Scotland Yard seemed to be either incompetent or obstructive. Senior officers appeared determined to limit the scope of the inquiry into the activities of the private investigator, Glenn Mulcaire, undertaken on behalf of the News of the World.

The establishment of Operation Weeting in January was supposed to signal a fresh start for the Met in the investigation. We were informed that Scotland Yard was now treating the matter with special seriousness and that they would "follow the evidence trail to its conclusion". But the latest twist in the saga casts doubt on whether the Met really did turn over a new leaf.

It has emerged this week that Scotland Yard is in possession of a considerable amount of material about the activities of a different private investigator, Jonathan Rees. His associates claim that Rees was engaged in a variety of illegal information-gathering activities on behalf of the News of the World and other newspapers. And the activities that Rees is alleged to have carried out make what Glenn Mulcaire did sound almost like child's play. Rees is accused of targeting senior politicians, members of the royal family, terrorist informers, officials at the Bank of England and even high-ranking police officers.

And yet when the Labour MP Tom Watson wrote to Sue Akers, the head of Operation Weeting, to ask about these allegations regarding Rees, the MP was informed that although evidence did exist, it could be "outside the inquiry's terms of reference". While Ms Akers seems to be conducting a robust inquiry into phone hacking, the Met's failure, so far, to include Rees within that inquiry does not, to put it mildly, inspire confidence.

In a letter to this newspaper today, the Metropolitan Police Commissioner, Cressida Dick, confirms that the allegations against Rees do indeed fall outside Weeting's terms of reference. However, she reveals that the Met is conducting a "formal assessment process" of the information in its possession regarding Rees. To which the appropriate response is: why has it taken Scotland Yard so long to look into this information? And was the Met really taking these allegations seriously before they were publicised this week? Scotland Yard's previous behaviour, sadly, leaves room for doubt.

What all this emphasises is the folly of leaving this investigation in the hands of the Met. The Met has long had a cosy relationship with the tabloid press. Rees himself is known to have had extensive links with Scotland Yard. Charging the Met with investigating phone hacking and illegal information gathering on behalf of newspapers was always akin to asking Scotland Yard to investigate itself. The investigation should have been handed to an outside force; one not compromised by links with newspapers.

It is probably unrealistic to expect the investigation to be taken away from the Met. But it is now imperative that the terms of Operation Weeting be extended to cover the allegations against Rees, or for another unit to be established that will investigate them with all the seriousness with which the Mulcaire case is supposedly being treated. There is also an increasingly powerful case for a public inquiry into not only phone hacking and illegal data collection, but the links between Scotland Yard and the tabloid press. There is a great deal more at stake here than the reasonable expectation of privacy of those in the public eye. This concerns the rule of law itself and the integrity of those charged with upholding it.