Police are appealing for information after two properties in Poynters Road were targeted by rogue traders on Saturday, August 20.
Two victims were both tricked into handing over more than £2000.
Three men knocked on the doors of two properties in Poynters Road, Dunstable, between 1.30pm and 3.30pm, they told the victims urgent building work needed to be carried out on their homes.
The offenders made off with the cash and never returned to carry out the work.
The men are described as white, with Irish accents and were diving a van that is believed to be white or yellow in colour with Irish number plates.
Detective Constable Andrea Crouch, investigating, said: “These men targeted two vulnerable victims and took advantage of them, cruelly conning them into handing over substantial quantities of cash.
“I am keen to speak to anyone who can help in finding those responsible.
“We believe they may have knocked on other doors down the road that day and would like to speak to anyone who noticed any suspicious activity or who saw the van or group of men in the area to get in touch.
“If you’re in any doubt that someone who knocks on your door is not there for a legitimate reason, do not let that person into your home.
“Report any information or suspicious activity you see to police by calling 101.”
Anyone with any information is asked to contact DC Crouch on 101 quoting crime reference number JD/33950/16.