London 2012: Train cable theft 'may affect Olympic travel'
8 November 2011 Last updated at 17:28 GMT
There are now as many as eight cases of attempted cable theft from the railways a day, operator Network Rail has said.
Dyan Crowther, the body's operations director, said the crime was spreading across the UK and had cost the firm more than £40m over the past two years.
Ms Crowther told the Transport Select Committee that cable theft could disrupt travel during the Olympics and measures were being put in place to manage it.