A fire which forced 80 people to be evacuated from a train travelling from Skipton to Leeds was caused by poor workmanship, an investigation has revealed.

A Health and Safety Executive inspector discovered insulation on an electric cable on the train had failed because it was installed badly.

Nigel Patterson, managing director of Northern Spirit, told the Telegraph & Argus that a swift examination of all its rolling stock had been carried out as a result of the findings.

"We instigated an immediate check on all trains of this type and no others were found to have this problem," he said.

"We are satisfied that the fault was an isolated one, specific to one train and as a result of work carried out 11 years ago before the trains were transferred to this region."

Passengers fled the carriages when flames licked the outside of the 11.24am Northern Spirit Service as it pulled up five miles outside Leeds Station on September 5. They were unhurt and led to safety at the former Armley railway station as firefighters doused the blaze at 12.15pm.

Rail user groups believe the problem may be due to the age of the trains which have been operating on the line.

Helen Kidman, chairman of Wharfedale Rail Users' Group, said: "The trains are 40 years old and when they come out of service in January, they won't be going anywhere. Clearly, health and safety is the most important issue on a railway. The consequences are too horrific to think of if the train had not stopped in open railway."

Tim Callow, chairman of the Airedale Valley Rail User Group, said: "It is certainly a warning for the future that standards need to be high with electrical insulation. These are 40-year-old trains and standards moved on a long time ago."

An HSE spokesman said the insulation had a very sharp bend in it, which caused it to perish.

This meant that it ignited other material, such as grease, which was under the carriage. A slight leak of oil from a transformer made the situation worse.

"It's very unusual that insulation on cable fails," he added.