Four soldiers returning home from Afghanistan were ordered off an East Midlands Trains service to London by an inspector.
The soldiers were returning from Helmand Province but their flight was diverted from RAF Brize Norton.
It meant their rail warrants, issued by the MoD to soldiers who can use them instead of tickets, were not valid, but a passenger stepped in and paid.
East Midlands Trains has issued an apology.
'Extremely sorry'
The soldiers' flight into RAF Brize Norton in Oxfordshire had been diverted to East Midlands Airport on 7 January.
They were forced to catch a train from East Midlands Parkway station but were told their rail warrants were not valid.
An East Midlands Trains spokesman said: "We are extremely sorry for the way the soldiers were treated.
"The soldiers were let down and our managing director will be making a personal call to the captain travelling with the group to apologise.
"Particularly in the recent severe weather, our staff have been instructed to use their discretion in assisting passengers unable to undertake their normal journeys and a similar approach should have been taken in this case."
I'd send the train inspector to Helmand Province!
