Reliability of News International's email trawl is questioned

Hacking inquiry may be delayed after Murdoch firm admits to 'technical issues' with data search

Mary Ellen Field, the former advisor to Elle MacPherson, is suing NI (Getty Images)

The reliability of News International's trawl for internal emails relating to the phone-hacking scandal was thrown into doubt at the High Court yesterday, as the firm admitted there were "technical issues" with its software.

The newly discovered problems with NI's computer database search emerged as the company was forced to ask for the postponement of a hearing in its case against Mary Ellen Field, a former adviser to model Elle Macpherson.

Ms Field is claiming compensation from NI after being sacked by Macpherson, who blamed her for leaking a series of stories to the tabloid press. Macpherson was a victim of News of the World phone hacking, which Ms Field claims was the actual source of the articles.

NI wants her case dismissed, claiming that Macpherson's phone was hacked only after Ms Field was sacked.

But yesterday NI's counsel Michael Silverleaf QC admitted that there were newly discovered "technical issues with data extraction software" that required a postponement.

He told the court he did not know if the software difficulties were affecting the "integrity" of data searches at NI, which have been previously conducted in conjunction with the Met's Operation Weeting investigation. Earlier this month at a hearing of the latest wave of civil actions brought by victims of phone hacking, it was revealed that NI had disclosed just 12 internal emails from a data trawl that focused on the period 2000 to 2005.

NI has spent £1m on what the Metropolitan Pol-ice has termed "disclosure searches" of its databases and archives. Other document searches and forecasts for similar exercises next year will take the cost of the overall data trawl past £7m. Last year Scotland Yard admitted it was involved in searching 300 million NI emails as part of investigations into phone hacking at the publisher's now-closed Sunday tabloid, the News of the World.

Evidence found in databases that had been thought "destroyed", but were subsequently reconstructed, has been crucial to the Met's investigation of hacking and the bribery of public officials.

The revelation of problems with NI's email trawl comes barely a week after Mr Justice Vos, the judge in the second wave of civil actions, ruled that further disclosures from the Rupert Murdoch-owned company's databases could not be justified.

In the Royal Courts of Justice yesterday, Mr Silverleaf could not give assurances that the newly discovered "technical issues" would not affect the rest of civil and criminal actions going through the courts.

Following the postponement of Ms Field's case, her lawyer Mark Lewis, who has been a key legal figure throughout the hacking scandal representing a number of high-profile victims, said: "This raises questions of reliability of [NI's] reconstruction of missing documents. It may be that we will now never know the full extent of this documentation." He added: "This has a wider impact. Not just about Mary Ellen Field, but an impact on all other cases."

Ms Field's case will now be heard in November after NI was given time by Mr Justice Vos to re-ex-amine the extent of the data extraction problem.