Residents could be shelling out hundreds of pounds every year for water services they don't use.

The issue came to light after Southern Water agreed to pay compensation to an elderly man after he discovered he had wrongly being charged for the past 27 years.

There could be many more customers who are paying the company for services they do not receive.

But the water watchdog has decided it is up to residents to find out for themselves - leaving open the possibility that vulnerable customers may wrongly continue to pay the bills.

The situation emerged after Southern Water was contacted by an 89-year-old, who asked not to be named, who lives in a village near Chichester with his wife, who suffers from Alzheimer's.

His main supplier is Portsmouth Water Company but he was billed by Southern Water for waste water services every year - despite there being no public sewer in his village.

Industry watchdog Ofwat said water companies were not obliged to check if homeowners were being correctly charged for waste water and that it was up to customers to raise the issue.

For more information about the rules concerning waste water charges, visit