British Transport Police are appealing for information after railway sleepers were placed across the railway line to Ironbridge Power Station in Telford.
The sleepers were discovered when a train was forced to stop in order to avoid hitting them on Sunday, September 19.
BTP investigating officer Emma Salter said: “This was extremely dangerous and could have led to a train being derailed and people being injured.
“Obstructing the railway is a very serious offence and anyone who puts objects on the track is risking up to 10 years in jail.
“We are working to identify who is responsible for this and are calling on members of the public to come forward with information that might help our investigation.”
Following a search of the area, police found that a wall or barricade had been constructed in a culvert near to the line.
“Clearly someone is accessing restricted parts of the railway,” PC Salter added. “Anyone who goes onto the railway line is risking their safety. They are also committing trespass.”
Anyone with information is asked to call BTP on 0800 40 50 40.