Over 50 trout have been killed in a suspected pollution incident at a Welsh lake.
The Environment Agency is investigating the incident which happened at a private fishing pond in Welshpool, Powys, which feeds the Lledan Brook.
The agency pumped oxygen into the water overnight to help the remaining fish survive. The operation may continue through the weekend.
A spokesman said: "We are very grateful to the member of the public who contacted us about this incident. This pollution is suspected of already killing 50 trout so it is important to contain it within the lake".
"We need to find out where it has come from and how it got there to try and avoid a repeat incident.”