An environmental body is probing reports oil has once again leaked into ponds.
Visitors to Westburn Park in Aberdeen saw oil in Gilcomston Burn several times towards the end of last year, prompting Scottish Environment Protection Agency (Sepa) officials to take action.
They located the source last month and hoped their measures stopped the leak.
However more oil was spotted yesterday.
Keep up to date with the latest news with The Evening Express newsletter
A Sepa spokeswoman said they were aware of reports an “oily film” had been seen in the ponds.
She added: “We are investigating the potential cause.
“Investigations into pollution of the ponds at Westburn Park are ongoing and complex due to the large number of potential sources.
“In addition to the natural supply of water which flows into the park, the ponds also take surface water drainage from surrounding areas of the city.”