A MASSIVE blaze on the Olympic Park was caused by workers accidentally setting fire to polysterene, the Olympic Delivery Authority (ODA) has revealed.

Last Monday a derelict warehouse in Waterden Road, near Stratford, was ablaze for more than five hours, sending smoke billowing across east London.

The ODA published its findings from its investigation into the fire this morning.

It found that workers clearing the site for demolition ignited insulation material while using a torch to cut steel piping.

The ODA has now suspended the use of welding torches until a review of its working practices has been carried out.

Although the building contained asbestos, the ODA said that none was found in the air, dust and debris around the warehouse after the fire.

ODA chief executive David Higgins said: "These findings confirm initial indications both that the fire was caused by accident while the warehouse was prepared for demolition and that poublic health was not put at risk.

"However this was a serious incident and we are instigating a thorough review of our stringent health and safety procedures as a result."

The London Fire Brigade is yet to conclude its own investigation into the blaze.