Keighley householders are being urged to be on their guard against bogus callers trying to con people into needlessly buying water filters.

It follows reports of residents in the Aire Valley being approached by people claiming to be from “the water board”, and saying tests have shown dangerously high levels of chlorine in the water.

The caller then offers to install a filter, at a cost of over £2,000.

Yorkshire Water (YW) says it has not been visiting properties in the area to install such filters, nor has any company on its behalf.

YW spokesman Matthew Connell said: “As sad as it is, there are appalling people are out there looking to con the vulnerable.

"The people who carry out such acts are quite simply despicable, and we want to make sure no one falls victim to their criminal activities.

"It's very rare that we visit customers' properties, so people should always be wary if they receive someone on their doorstep claiming to be from the company. If this does happen, we ask all customers never, ever, to let the caller into their property without fully checking all their credentials. And if you're not convinced, simply don't let them in.”

He added: “We would like to reassure all our customers that there is no reason to think that their tap water is unsafe to drink. It has to pass a number of stringent water quality tests before it is released for human consumption.”