While at least 59 journalists have been arrested over the last two years for alleged information crimes, the Serious and Organised Crime Agency has refused to disclose the names of blue-chip companies involved in similar activity.
SOCA chairman Sir Ian Andrews told the Commons Home Affairs Committee that releasing the details "substantially undermine the financial viability of major organisations by tainting them with public association with criminality".
Sir Ian was asked to supply the information which it gathered in Operation Millipede after appearing before the committee earlier this month. It emerged last month that a 2008 SOCA report – which shows that most hacking and blagging of information is carried out by law firms, telecoms and insurance companies – was submitted to the Leveson Inquiry last year but never published or discussed.
The failure of national policing body SOCA to act against the companies has been contrasted with the current Met police investigations into newspaper journalists who allegedly used private investigators to obtain information through phone-hacking.
In a letter to the committee chairman Keith Vaz, Sir Ian wrote: "Given the lack of certainty over guilty knowledge on the part of Operation Millipede clients, and the impact that any publication might have on those named (recognising the requirement for public authorities to have respect for individuals' private and family life under the Human Rights Act 1998), together with the possible prejudice which any publication might have on ongoing criminal investigations and future regulatory action, the list of Operation Millipede clients which SOCA has created following your request has been formally classified.
"This reflects the fact that the information it contains, if published, might prejudice individual security or liberty, impede the investigation (or facilitate the commission) of serious crime or substantially undermine the financial viability of major organisations by tainting them with public association with criminality."
Vaz said he would now be writing to every firm in the FTSE 100 and to the top 100 legal firms to ask them to declare whether they have commissioned private investigators, and for what purpose.
"SOCA has indicated that it is prepared to give the client list to us in confidence. This has still not been received. It is a disappointment that this is yet another document the committee has had to receive in secret from SOCA," he told The Independent.
"In view of the public interest, openness and transparency may be the only way that the public can be reassured that no-one is above the law and (that) Soca have done all they can to address this issue."
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