At the heart of the affair is a data company, Essential Computing, based near Bristol. Staff there have been interviewed by Operation Weeting. One source speculated that this company had compelled NI to admit that the archive existed.
The Guardian understands that Essential Computing has co-operated with police and provided evidence about an alleged attempt by the NI executive to destroy part of the archive while they were working with it. This is said to have happened after the executive discovered that the company retained material of which NI was unaware.
The alleged deletion has caused tension between NI and Scotland Yard, who are also angry over leaks. When it handed over evidence of journalists' involvement in bribing officers, it wanted to make an announcement, claiming credit for its assistance to police. NI was warned that this would interfere with inquiries and finally agreed to keep the entire matter confidential until early August, to allow police to make arrests. In the event, a series of leaks this week has led Scotland Yard to conclude that NI breached the deal.