DOUBT has been cast over whether the security scanning of containers bound for the US from Southampton docks will continue after questions were raised over the financial feasibility of the move long term.

The city's docks were among the first ports in the world to start scanning containers destined for the US for nuclear materials as part of a move to step up homeland counter terrorism measures.

The six-month pilot scheme aimed to prevent terrorists detonating a nuclear or dirty bomb by stopping any of the potential materials being shipped into the country under new US legislation During the pilot scheme some 90,000 containers were checked for radiation at the gates of the port with a further 5,500 containers bound for the US x-rayed using state of the art equipment that shows the contents without having to open up the container and search it.

The equipment operated by British company Smith's Detection works by using infrared equipment that is able to penetrate metal containers, x-ray the contents and then distinguish cargo in a colour-coded image. Organic materials like drugs and explosives are coloured bright orange and non-organic materials are coloured blue.

The trial, which included similar schemes at several ports around the globe, started in October and came to an end last month. It is estimated to have cost $18m.

However, it has been reported that the European Union has expressed concern over the long term feasibility of the programme after it was calculated that imposing the scanning of all containers would cost in the region of $500 a unit to US trading partners, based on simple calculations.

The Union has also expressed concern that some smaller ports would lose out as the US trade would be directed to the larger ports, with the facilities to cope with the scanning process.

At the time of the unveiling of the project Southampton Container Terminal managing director Campbell Mason said they were looking forward to working with the US and UK authorities improving the security of goods around the world.

However, a spokesman yesterday said they were unable to comment about the trial or whether it would be continuing. No one from the Department for Homeland Security in the US was available for comment.