Sinclair Oil Corp. is offering a $25,000 reward for information about an apparent sabotage attempt at its refinery near Rawlins.
Workers discovered damage to a number of valves on Oct. 18. after noticing strange feedback from instruments on a hydro-cracking unit.
Company spokesman Clint Ensign told the Casper Star-Tribune that the company concluded the damage was intentional but wouldn't comment on whether there were signs of a break-in.
Sinclair Police Chief Jeff Sanders confirmed Wednesday that his department is investigating. FBI spokesman Dave Joly wouldn't confirm or deny whether his agency is involved but Wyoming Occupational Safety and Health Administration spokeswoman Hayley Douglass said the FBI is investigating.
The refinery has had several accidents and releases over the past several years.