More than 30 fish and newts, which are protected by law, have been killed after bottles of detergent were emptied into Manor Park pond, south London, last weekend.

The incident has been described as a senseless and cowardly act by Sutton Council who are appealing for information to help catch the culprits.

Following the death of the Sutton park pond life on April 7, local residents have expressed their outrage at the crime.

One resident, who wished to remain anonymous, said: "I am very angry. Why would people do that? It is just ruining it for everyone else. I have three kids and I had to explain to them why the fish were dead. I just can't understand who would do something like this."

Maureen Peglar, trustee of Ecolocal in Carshalton, warned that if people continue to contaminate water there will be serious consequences for the borough's wildlife. She said: "It will kill the wildlife and encourage vegetation to grow. When they die they will sink to the bottom and use up all of the oxygen. Then the fish left will die of oxygen depletion."

A spokesman from the council said the authority and the police were invesigating the incident. "A detergent is alleged to have been poured into the water killing over 30 fish, including newts.," he said.

"This was a senseless and cowardly act, which has caused serious damage to the local wildlife. We urge anyone with information about this incident to come forward. Please call either Sutton Council on 020 8770 5070 or Sutton Police on 020 8643 1212."