AN investigation has been launched by the Environment Agency after acid, containing arsenic, was spilt into the River Skerne.

The investigation team is still looking into how the incident occurred, at Filtronic, in Newton Aycliffe.

A spokeswoman said: "We were informed acid solutions, containing various metals, had been spilt into the River Skerne and launched an investigation immediately.

"We were aware the solutions contained arsenic and, as most people know, this substance can cause respiratory problems, which was cause for concern.

"We have carried out tests and initial results appear to suggest the spillage has not had any serious effect on the river, as we found it teeming with life. The readings were below the quality standard level for arsenic, so should not pose a problem.

"However, we have taken samples for further tests which we believe will confirm this."

Filtronic makes compound semiconductors for mobile phones, which makes it possible for them to be used abroad.

Chief executive John Rolston said: "From time to time we do get small spillages that we collect in tankers and they are taken away. However, there was a very small leak from the tanker.

"We immediately called the Environment Agency and Northumbria Water and their tests, as we were convinced they would, showed there was no risk to aquatic life. We regret this incident happened."