TWO hackers who helped to launch a virus that caused computer chaos across the globe have been warned they are facing jail.

Andrew Harvey, 22, and Jordan Bradley, 20, were arrested following a joint swoop by Durham Police and US secret service and FBI agents investigating an international hacking group.

The group, known as the THr34t-Krew, created an internet worm that infected 18,000 computers around the world and caused disruption costing an estimated £5.5m.

The group is believed to have members around the world, mostly in their teens and early twenties. The North-East pair were arrested in a series of co-ordinated raids in the UK and US.

Bradley and Harvey last week admitted conspiracy to cause unauthorised modifications of computers with intent between December 31, 2001 and February 7, 2003.

In a basis of plea, which was not disclosed during the hearing at Newcastle Crown Court, the pair accept the quantifiable damage they caused was just less than £15,000.

Harvey, of Scardale Way, Belmont, and Bradley, of Bates Avenue, Darlington, were given bail to appear for sentence on September 30.

But Judge Beatrice Bolton warned them: "The reality here is the likely sentence is a custodial one."

One IT expert who tried to trace the virus, called tk, was amazed by the power wielded by the team of hackers. In a short space of time, he said, they had been able to gain control of more computing power than that enjoyed by many governments.

After their arrests, the pair were bailed and their cases were investigated by the London-based National Hi-Tech Crime Unit.

The Durham Police operation was observed by officers from the US government-run computer and technology crime hi-tech team.

The Hi-Tech Crime Unit was launched in 2001 and is hosted by the National Crime Squad with support from the Police, National Criminal Intelligence Service, the military and HM Customs and Excise.

It is the UK's first national law enforcement organisation formed to combat computer-based serious and organised crime.

The tk virus, which affects companies' ability to do business, lies dormant in infected computers until it is triggered by specific commands.