FURTHER tests have been made after chemicals were dumped in a river which had recently seen a recovery after being polluted for years.
People in Heckmondwike reported the River Spen turned white on Monday afternoon.
Environment Agency officers were immediately called in to check out the problem.
The agency has not yet revealed which company is being investigated, but legal action could follow.
The stretch from Heckmondwike to Ravensthorpe was polluted by a chemical which has not yet been fully identified.
Yesterday officers return- ed for a second day of testing. They reported no obvious effects to wildlife.
An Environment Agency spokeswoman said: "Although we don't know exactly what the chemical was, we are aware that it could have caused some irritation to skin - so people need to stay out of the water and keep pets away as well for the time being.
"Three officers went down to the river and began taking samples immediately. This is very disappointing because we had done a lot of work to clean this part of the river up and it was doing very well.
"We are now carrying out further investigations to try and find out exactly what damage has been done.
"Fish have been spotted alive in the water, but it is far too early to say what the overall damage to the wildlife is."