There are currently eight cases of cable theft per day from railways, operator Network Rail said today.
Ms Dyan Crowther, the operations director of the organisation, said that the crime has been spreading across Britain and has cost the firm over £40m in just the past two years.
While most cases were random, as the MPs were told, there is evidence that thieves have been impersonating engineering staff.
A police officer of seniority said that rail cable theft is viewed as being a low risk crime with high returns and also pointed out that penalties aren’t tough enough.
Ministers say that they are looking at taking new measures that will combat the problem while being urged to hand police much greater powers and tighten regulation of all scrap metal dealers.
The Transport Select Committee was told by Ms Crowther that the problem of theft first surfaced across north-eastern England around two years ago but has since “migrated” across the country at a steady rate.
While the vast majority of cases took place in the evening, thefts are now regularly happening during peak times, she told MPs. It was added that while there are certain “hotspots” the authorities have been unable to find any real pattern to the occurrence of theft.