WATER experts say a mystery substance which was spotted spreading through a river posses no risk to the public.

Concerned walkers reported the unusual murky cloud to environment officials and water company Anglian Water when it appeared in the River Brain, in Witham.

Anglian Water sent workers to the site to take a sample of the water and thankfully the results came back clean.

Experts say it might have been caused by the dumping of waste down a nearby drain.

Sue Plumb, of Guithavon Road, Witham, was out with her father walking her dog along River Walk when she spotted it and reported it to authorities.

She said: “It was quite weird because it was coming out of one of the pipes - it looked a bit like milk.

“It was worrying because it’s where people walk their dogs and we just didn’t know what it was.

“There’s plenty of wildlife around there too but thankfully it sounds as though it wasn’t toxic.

“It’s a shame some people don’t just show a little bit more respect because it’s a lovely area.”

A spokesman for Anglian Water said: “As soon as we were alerted to a substance in the river in Witham an engineer was dispatched to investigate.

“All our equipment was found to be in working order and the substance is not from our water recycling processes.

“Sometimes, cloudy or murky water is caused by the incorrect use of nearby surface water or rain drains.

“As their name suggests, they are meant for rain water only. “Disposal of waste water or chemicals down these drains can lead to pollution as they flow directly into our rivers.

“We would always encourage customers to report any suspicious substances to us so we can investigate as soon as possible.”

Anglian Water can be reached 24 hours a day, seven days a week, by calling 03457 145 145.