Detectives from the US last night questioned two North-East men arrested after a worldwide manhunt into a devastating computer virus.

Jordan Bradley, 19, of Darlington, and Andrew Harvey, 21, of Belmont, Durham City, were held during dawn raids carried out by local police yesterday.

They were interviewed by members of the US Computer and Technology Crime Team - who travelled from California to the North-East - and later released on bail.

The team was set up as part of a US Government crackdown on computer fraud, spearheaded by the FBI.

Yesterday's operation was carried out by Durham Police and the London-based National Hi-Tech Crime Unit (NHTCU). Officers also removed PCs and ancillary equipment from both houses.

A few hours later, police in America arrested a third man, following a raid on a house in Illinois.

The raids follow a world-wide hunt for a team of hackers known as THr34t-Krew - Threat Crew - suspected of creating a computer virus with terrifying power.

The virus - known as a Trojan because it hides in an innocent looking e-mail file - allowed hackers to take over entire company networks downloading files and wreaking havoc with confidential data.

One IT expert who attempted to trace the malicious virus, called tk, was amazed by the power wielded by the 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.

Police say the virus infected an estimated 18,000 computers worldwide, including many in the UK. The cost of the disruption is estimated at £5.5m.

The North-East suspects were taken to Darlington police station for questioning about offences committed under the Misuse of Computers Act 1990.

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

Once activated, it splits itself from one file into 30, changing programs, settings and services that start up when a PC is switched on. It also adds a file transfer programme, which allows hackers to gain control.

Offensive capabilities include distributing copies of itself to other computers, attacking specific systems or swamping networks with cyber-junk bringing companies to their knees.

Detective Superintendent Dave Jones, of Durham Constabulary's head of intelligence, said officers from the force's computer crime unit and specialists in southern California had been working closely together during the past month planning the operation.

Police arrested Jordan Bradley, an apprentice electrician, at the address he shares with his father in Bates Avenue, Darlington.

His father, who refused to give his name, said: "Jordan was arrested and I am very concerned about him.

"He is an apprentice electrician but computers are his hobby.

"It came as a complete shock and at the moment I don't really know what is happening or what they think he has done."

A neighbour said: "They only moved in about six months ago and seem to lead a very quiet life.

"Jordan is a nice young lad, quiet and polite. I couldn't imagine him being involved in anything serious."

In Durham City, neighbours were shocked at the arrest of Andrew Harvey, who lives with his father in Scardale Way, Belmont.

One woman said: "I am just flabbergasted that he has been arrested for anything at all, let alone something as serious as this."

Detective Superintendent Mick Deats, deputy head of the NHTCU, said virus writing and hacking were serious crimes which cost UK firms millions of pounds in lost business and downtime. "Incidents of hacking, viruses and worms are increasing rapidly," he said. "Our task is to track down the people responsible."

American computer expert Seth Fogie first became aware of the THr34t-krew after he was called in by a business which was having difficulty with its Internet connection.

After a thorough investigation, Mr Fogie discovered hackers had taken over the computer and had turned it into a server containing more than 3GB of illegal software.

He later tracked a link to the gang's web page, which has now been taken offline.

In one incident, Mr Fogie chatted online with a 16-year-old from England, believed to be a member of the gang, who told him the security measures that the gang adopted to maintain anonymity.

In an article detailing his investigation, Mr Fogie said: "This 16-year-old and the other members of his Krew had created a worm that had more power and bandwidth than some governments."