Mr Lamb, from Askham Croft, was found on Thursday morning when a train driver noticed his body on the tracks. An inquest into his death is expected to be opened next week.
A spokesman for British Transport Police said: “We have now passed on all the details to the coroner and an inquest will be opened on Tuesday. We are not treating the death as suspicious.”
British Transport Police said earlier the dead man’s injuries had been consistent with someone “having been struck by a train.”
It is understood Mr Lamb leaves a widow.
The East Coast mainline was closed south of York throughout Thursday morning as emergency services carried out an investigation and removed Mr Lamb’s body.
The stretch of line near Copmanthorpe has been the scene of many deaths in recent years.
In April 2011, a 52-year-old man was hit by the train on lines close to Temple Lane, in the village, in the early hours of the morning.
And in 2006, another man was killed by a train near Moor Lane in Copmanthorpe, when the car he was driving crashed through a fence into the path of a passenger train.”