Under enormous legal and political pressure, Murdoch has ordered that the police be given everything they need. Whereas Scotland Yard began their inquiry a year ago with nothing much more than the heap of scruffy paperwork seized from the NoW's private investigator, Glenn Mulcaire, Murdoch's Management and Standards Committee has now handed them what may be the largest cache of evidence ever gathered by a police operation in this country, including the material that led to Saturday's arrests.
They have access to a mass of internal paperwork – invoices, reporters' expense claims, accounts, bank records, phone records. And technicians have retrieved an enormous reservoir of material from News International's central computer servers, including one particularly vast collection that may yet prove to be the stick that breaks the media mogul's back. It is known as Data Pool 3.
It contains several hundred million emails sent and received over the years by employees of the News of the World – and of the three other Murdoch titles. Data Pool 3 is so big that the police are not even attempting to read every message. Instead, there are two teams searching it for key words: a detective sergeant with five detective constables from Scotland Yard working secretly on criminal leads; and 32 civilians working for the Management and Standards Committee, providing information for the civil actions brought by public figures and for the Leveson inquiry and passing relevant material to police.
For News International, Data Pool 3 is a nightmare. Firstly, no one know what is in there. All they can do is wait and see how bad it gets.
Second, the police clearly believe it may yield new evidence of the crimes they set out to investigate – the "blagging" of confidential data from phone companies, banks, tax offices etc; the interception of voicemails and emails; the payment of bribes to police officers.
Third – and most nightmarish – Data Pool 3 could yield evidence of attempts to destroy evidence the high court and police were seeking. Data Pool 3 itself was apparently deliberately deleted from News International's servers.
If proved, such conduct would be serious because it could see the courts imposing long prison sentences; and because it could have been sanctioned by senior employees and directors.
The Guardian last July revealed police suspicions that a huge number of emails had been deliberately destroyed. Since then, high court hearings have disclosed more detail. Late in 2009, News International decided to delete old email from their servers. This appears to have been a simple piece of electronic housekeeping. However, the plan was not executed.