Police are warning people to be on their guard after a suspected burglar tricked his way into a pensioner's house.
A man believed to be about 30 years old called at the property in Millfield Avenue, Walthamstow, at 5pm on January 8 and said there was a problem with the water mains in the street.
He then said he needed to gain entry to check the house supply.
The occupant led him to the kitchen but became suspicious when he saw the suspect talking to someone at the front door.
The bogus caller then left when he was then told the homeowner was expecting a visitor.
Detective Constable Ray Anderson said: "We cannot emphasise enough that utility companies such as water, electricity and gas, would normally contact you prior to undertaking any works.
"Do not be concerned about keeping callers waiting while you check their identity.
"Any genuine caller will not mind waiting. If you are suspicious, then call us. If in doubt, keep them out. If you have an elderly or vulnerable neighbour, please let them know about this incident.
"We want to raise awareness and prevent anyone becoming a victim to these appalling crimes."