Detectives have appealed for help after a man in his 90s fell victim to a sneak thief.
Police say a man claiming to be from St Helens Council called on the pensioner at his home in Junction Road, Rainford, at around 2pm on Sunday.
He claimed that a water valve had burst and he needed to inspect the water supply inside.
But while the elderly man was distracted, the intruder stole cash and left.
The suspect is said to be white, in his 40s, around 5ft 9in tall, and spoke with a 'posh English' accent. He also wore dark clothing, a hat and gloves.
CCTV, forensic and witness enquiries are currently ongoing and officers are appealing for anyone with information to get in touch.
Chief Inspector Steve Brizell said: "This was a deplorable offence against an elderly man which has left him feeling understandably vulnerable and distressed.
"We are supporting him at this difficult time and I want to assure people that we will act on any information given to find those responsible.
"It's hard to believe that anyone would stoop so low as to con their way into the home of an elderly person and steal money.
"If you live in the Rainford area and have recently been visited by anyone claiming to be from the council or doing any work on water pipes, please let us know.
"Likewise, if you have home CCTV and have recently seen anyone who matches the description or was claiming to be carrying out work, please come forward."
Witnesses are being asked to call the non-emergency number, 101, quoting log number 0517243120 or the Crimestoppers hotline, in confidence, on 0800 555 111.