Suicide attacks cost under £140,000 to carry out

The FBI has stepped up its probe into who backed last week’s suicide hijackers as it was revealed the attacks could have cost less than £140,000 to carry out.

The bill in the aftermath of the attacks will run into billions of pounds, with the American Government already committing cash to the rescue effort, propping up the airlines and massive troop deployments.

Meanwhile investigators upped the pressure on the terrorists’ support network, revealing they are now looking for an older man who they suspect played a key organising role in the attacks.

The man, who has not been named, has greying hair and witnesses in at least two states have told detectives they saw him visit the hijackers in the months leading up to the attacks on September 11.

They are linking his role to that of other terrorist missions ordered by Osama bin Laden, where young fanatics were directed during the final run-up to the incident by a senior leader from the Al Quaida organisation.

The hunt came as officials told the New York Times that the cost of carrying out the attacks could be as little as £137,000.

The cash was used to pay for flight training for some of the 19 hijackers as well as housing, car hire, air travel before the attack and the tickets which let them on to the doomed planes.

The relatively small amount of cash spent - the equivalent of less than £7,000 for each hijackers - will make it difficult to trace its origin, but the men are believed to have had a single source for their money.

Investigators also revealed they are looking into the backgrounds of the each of the 19 men and have found they were better-educated, more middle class and more Westernised than previous terrorists connected to bin Laden.

Some even visited Las Vegas to gamble and go to shows while they lived in America.