An Angus councillor has asked the public to help police identify a group of youths linked to the derailment of a train at Inverkeilor.
Bob Spink, who lives in the village, has asked residents to contact police if they spotted youths near the tracks on the night before the incident.
The front wheels of the Edinburgh to Aberdeen CrossCountry train came off the rails at Inverkeilor at 9.45am on Sunday November 4.
British Transport Police think an object was put on the line deliberately and believe tracing the youngsters may be vital to solving the case.
Mr Spink said: ”I would ask anybody with any information at all, no matter how slight or unimportant they think it is, to get in touch with the police and let them know so they can check it out.
”If they’ve any worries about doing that, then they can get in touch with me. I’d be happy to take any messages and pass them on.”
Officers say the group consisted of four people who ranged from 5ft to 5ft 6in tall. One of them was wearing a grey or light-coloured hooded top and trousers.
It is not known whether they were male or female.
Detective Chief Inspector Iain Miller, who is leading the investigation, said: ”The youths were seen walking towards Bryanton House, just off the A92.
”This would have been prior to the bonfire at Inverkeilor on the night before the incident occurred.
”It is important to trace these youths in order to eliminate them from our inquiries.”
Police also want to speak to anyone who attended the bonfire or who took photographs that evening.
A £25,000 reward has been offered by the rail industry to anyone who can help police find those responsible.
None of the 36 passengers on the derailed train were injured but the 49-year-old driver was treated for a minor head injury.
British Transport Police can be contacted on 0800 40 50 40 or anonymously via Crimestoppers on 0800 555 111.
Tayside Police are assisting in the investigation.