A ScotRail driver who failed a drugs test has resigned the day before a disciplinary hearing, The Scotsman has learned.
Steve Kenny tested positive in a routine check after his train derailed last month due to a suspected track fault.
He was suspended after the standard drugs and alcohol test following the incident in Stonehaven.
It later emerged he had failed another ScotRail drugs test eight years ago while working as a train ticket examiner.
He is believed to have been caught during health screening as part of his application to become a train driver.
Mr Kenny, who is believed to be in his 30s, resigned and is understood to have gone on to become a driver at First Great Western in England before returning to ScotRail as a driver.
An industry source said: “He resigned the day before the disciplinary hearing.
“He wasn’t asked to go, but clearly he knew what the outcome of that was going to be and went before it wasn’t his decision.”
There had been surprise that Mr Kenny had been re-employed by ScotRail after failing a drugs test.
But there is also a belief among parts of the industry that people should be given a second chance.
However, the Scottish Conservatives said rail companies must share information about staff failing drug tests.
Transport spokesman Jamie Greene said: “The fact the driver was allowed to operate ScotRail and First Great Western trains, despite failing a drugs test in 2010, does raise some serious questions about ScotRail’s procedures.
“Rail operators should consider how they can improve sharing information on serious misconduct to prevent this happening in the future.
“There are very clear reasons these policies are in place.
“Driving a train carries huge responsibility, including the safety and wellbeing of passengers.
“Passengers will no doubt feel let down by this serious procedural failure.
“The responsibility now lies with the Scottish Government to take the necessary action to prevent similar issues occurring in the future.”
ScotRail said it did not comment on staff.
Kevin Lindsay, Scotland secretary for train drivers’ union Aslef, said: “We do not condone anyone reporting for duty under the influence of drugs.”
In the 10 October incident, the empty train which Mr Kenny was driving derailed as it passed a set of points connecting tracks. It closed the Dundee-Aberdeen line for two days, causing major disruption to passengers.
British Transport Police said it had been caused by a points failure and no “criminality” had been found.
It said officers were not investigating the matter further.
The train is understood to have been travelling at less than the speed limit and did not pass a red signal.