The U.K.'s Serious Organised Crime Agency (Soca) has been ordered to make public a list of over 100 companies and individuals who hired corrupt private detectives. A government committee warned Soca that if it did publish the list by Monday, it would be forced to do so instead.
Keith Vaz, chairman of the Home Affairs Committee, accused Soca and its director general, Trevor Pearce, of "sitting" on the list for four years, despite knowing that the government was conducting a highly publicized investigation into the use of rogue investigators by the newspaper industry.
"The Committee is not very happy with the length of time it has taken for this information to be passed on, because we have been involved in looking at hacking issues for the last six years and we are very disappointed this has taken this long," Vaz told Pearce at a committee meeting on Tuesday afternoon.
The news follows revelations that the British police had known for years that some of the country's most respected companies had employed detectives who stole or illegally bought private information about business rivals.
Companies believed to have hired the investigators include accountancy firms, leading financial institutions and several pharmaceutical companies, as well as individual celebrities.
The four corrupt private eyes involved pleaded guilty to fraud in 2012 and were given prison sentences.
Vaz said that Soca, which has an annual budget of £0.5 billion ($0.78 billion), had only produced the list in the last six weeks due to British newspaper reports and pressure from the committee.
"I still am puzzled, and the Committee is baffled, about how you can have been sitting on this information for four years, without taking any action to ascertain whether any of the people, organizations and firms on the list you passed to this committee — and that you have now passed to the information commissioner — have been involved in any inappropriate activity," he said.
Two weeks ago The Mail on Sunday claimed that Deloitte, Credit Suisse and Chase Manhattan were among the financial firms named on the list, along with U.K. TV presenter Jeremy Clarkson. The newspaper stressed, however, that there was no evidence the companies or individuals concerned had deliberately hired the detectives to conduct illegal activities.
Referencing the public inquiry conducted into the British press following the News International phone hacking scandal, Vaz called last month for "Leveson Part 2" to be conducted into the use of private investigators outside the media. The first Leveson Inquiry into the ethics of the British press ended in November 2012.
(Read more: Ex-Murdoch Editor Brooks Denies Hacking Charges)
"At that stage, it was perceived to be a media problem, although it now has become apparent that the problem was much more widespread. The use of private investigators who have been engaging in criminality with impunity was shockingly rife, as confirmed by the categories of individuals, organisations and firms in the Soca list," Vaz wrote in a blog post.
—By CNBC's Katy Barnato