Edinburgh residents raised the alarm after spotting an 'oil slick' in the Water of Leith on Thursday, March 30.
Environmental experts have now launched an investigation after receiving a number of reports about a concerning oily appearance of the water.
The Scottish Environmental Protection Agency has confirmed that officers are investigating the 'oil spill' in Leith and are urging anyone with information that can help them to locate the source of the oil to get in touch.