A public health warning has been issued after toxic algae (benthic cyanobacteria) was found in the Selwyn River at Whitecliffs Domain.

In a statement, Canterbury Public Health said people should avoid the river and animals, particularly dogs, should not be allowed near the water until the health warning has been lifted.

There are also other access points along the Selwyn River that may have benthic cyanobacteria present.

People are advised to treat every low-flowing river cautiously, check for the presence of benthic cyanobacteria and avoid contact.