Police investigating computer hacking by private investigators commissioned by national newspapers have uncovered evidence that emails sent and received by Gordon Brown during his time as Chancellor were illegally accessed.

Mr Brown's private communications, along with emails belonging to a former Labour adviser and lobbyist, Derek Draper, have been identified by Scotland Yard's Operation Tuleta team as potentially hacked material. They are currently looking at evidence from around 20 computers which hold data revealing that hundreds of individuals may have had their private emails hacked.

The links discovered from the seized computers suggest that the email investigation could involve as many victims as those involved in the News of the World phone-hacking scandal.

The eight-strong Tuleta team is looking at the possibility that several Fleet Street titles commissioned specialist private detectives to access computers. News International said yesterday that NI has "no alleged link" to Gordon Brown and Derek Draper.

One of Mr Brown's former cabinet colleagues, Peter Hain, has confirmed that he held discussions with police investigating the potential hacking of his computers during the time when he was Northern Ireland Secretary.

The Tuleta team has also interviewed a former Army intelligence officer who made a complaint that his computer was illegally accessed six years ago as part of a search for documents associated with Martin McGuinness.