POLICE are investigating after residents received hoax calls warning their water supply was contaminated with sewage.

Several households in the Pickering and Scarborough areas of North Yorkshire received the recorded message at about 1.30am yesterday.

The automated call warned that sewage and storm water had got into the supply and the water was no longer fit to drink.

But Louise Wylie, spokeswoman for Yorkshire water, said the calls were hoaxes.

She said: "Yorkshire Water would never contact customers by telephone if we were asking them to boil water or to give a discolouration notice.

"If an emergency of this nature was to occur we would get people out on site to investigate.

"Anybody who receives a phone call on this matter is receiving a hoax call and there is no risk to customers.

"We do not know yet if it's just a prank or something more sinister and we are keen to see if there is a link between the recipients."

A spokesman for North Yorkshire Police confirmed they had been told about the calls and would be investigating.