Police are appealing for information following an incident of reckless conduct in the Balerno area.
Local officers responded to Harlaw Road on Friday evening after two large pools of oil were discovered on the road, near Harlaw Farm.
The oil affected the condition of the road and could have resulted in damage or injury to motorists who were unaware of its presence.
Police believe the oil was deliberately deposited and anyone who can assist with their enquiries is asked to come forward.
A police spokesman said: “Enquiries were carried out to determine whether any of the agricultural vehicles that regularly use the road were leaking oil. As this has not been the case, we believe this has been a malicious act and we are keen to speak with anyone who can help us trace those responsible.
“Oil on a roadway has the potential to cause a vehicle to lose control and anyone found to be involved in this will be robustly dealt with.”