'Ring of steel' proposal to safeguard Olympic Park

Olympic chiefs are considering building a "ring of steel" around the 2012 construction site which could be left in place to protect athletes once the Games begins.

Final plans will be drawn-up later this year as Olympic Delivery Authority leaders consider the best way to secure the 2.5km2 site.

And any perimeter fencing could be used as part of the security measures when the Games officially begin in 2012.

An Olympic source said: "A perimeter fence is an option we are looking at but the Games site is not like other building sites.

"We have to consider the issue of combining security we put in place during construction and the security that will be in use once our work is finished. Our security could be used during the Games and that's a consideration at this stage."

Site protection will have to be in place by 2009 when the construction phase gets into full swing.

Thousands of workers will have to pass face or handprint recognition checks to get access to the job from two main entrances to the site.

The source said: "Security will be ramped-up as the site progresses and next year we will be a lot more active on site and have more assets to protect."

An ODA spokesperson said: "The ODA has robust and appropriate security plans in place to ensure the venues and infrastructure for the London 2012 Games are delivered safely, on time and within the given budget. The nature of the security plans and responses are phased to fit each stage of the project.

"The Olympic Park is an 'island site' with managed access and as we move towards the start of construction next year security is being phased up. We are currently procuring an industry best practice access control system that will include biometric technology and a security guarding service to operate during the construction and legacy transformation of the Olympic Park.

"Within the 'island site' venue contractors will be responsible for the security of their own sites according to ODA requirements. As construction work ramps up in 2009, perimeter protection will be increased and details are currently being finalised."

An extra soil washing machine is due to start work on the Olympic site as ODA chiefs look to clean 750 tonnes of earth a day.

More than 1.5 million m3 of soil needs to be excavated, tested and cleaned before it is used to create ground levels needed for construction to start this summer.