"It's likely the pollutant was dumped directly into the pond. To address traces of remaining pollution, we flushed the pond with clean water from nearby hydrants.
"The pollutant appeared to be paint but the source could not be identified. The stormwater drains leading to the pond were dry and had no traces of the pollutant."
Council compliance operations manager Warrick Zander asked anyone who knew about the spill, or who sees anyone dumping anything into the pond, to contact the compliance team on 349 0001 or Horizons Regional Council's pollution line on 0508 800 800.
"We would welcome any further information," Zander said.