James and Jane Varey, who are both in their mid-seventies, live in a static unit.

Their worried son Frank, who lives next door, has been trying to get to the bottom of how his parents could have been confronted with such a huge bill.

He told the YEP: "Really they only have a TV, lights and a DVD player running in there so there's no way in the world they could have run up a bill like this.

"The exact amount is £2,647.57 and they are absolutely worried sick as they could never afford to pay that amount and have no idea where it could have come from."

The bill runs from February 27 to May 8 of this year.

Mr Varey Jnr says suppliers Npower have told them the bill is correct but he is determined to get to the bottom of how the charge could possibly be so high for a static unit which only measures 32m by 10m.

He said: "It would be practically impossible to run up a bill that large for a unit this size.

"I spoke to a bloke on the phone from Npower and when I told him how much the bill was, he asked if they were living in Harewood House! "

A spokeswoman for Npower said that the company were concerned about their energy consumption and had advised the couple that they would need to arrange for an electrician to check their internal electrical wiring.

They said a fault can affect the 'pull' on the electricity.

She added that once the wiring had been checked, the company could ensure that the bill was correct.

She said an extended repayment plan would be offered and the company will reduce the outstanding amount as a goodwill gesture - regardless of the outcome from the internal wiring test.

Mr Varey said for the same quarter period his parents would normally expect to pay around £360 and no more than £400.