An elderly Hove couple were tricked into handing £4,000 to a gang of fraudsters.
The conmen told the pensioners that their home, in Lyndhurst Road, was unsafe.
The victims were visited by a man calling himself Mr Graham who said that he was doing work on their neighbour’s house and had found water leaking through the wall.
He persuaded them that he needed to look inside their roof urgently and when they allowed him in he told them that if work was not done quickly the chimney could collapse.
He asked for payment of £4,000 for specialist equipment that he said he needed to do the work and a second man arrived the following morning and collected the cash.
“Mr Graham” then called the couple and said that he now needed £15,000 to complete the work.
He sent a third man to the home who drilled several holes in the wall of the roof and then left.
The victims only realised that they had been conned when they spoke to their neighbour who had no knowledge of the workmen.
PC Jane Everson, of the Brighton response investigation team, said: “The victims are very upset and embarrassed to have been tricked into handing over such a large sum of money by the fraudsters.
“This was a particularly cruel crime on two trusting people.”
The man who visited on Tuesday 16 July and gave his name as Mr Graham was white, aged in his thirties, 5ft 11in tall and of medium build. He had short blond or ginger curly hair with stubble and an Irish accent.
The man who collected the cash was white, about 18 years old and stocky with short hair.
The man who drilled the wall was white, about 18 years old, stocky and about 5ft 8in tall.