Police Scotland has warned householders in Dundee and Angus not to hire workmen who turn up on their doorstep unannounced.
The force issued the warning after three men knocked on the door of an 85-year-old woman in Monifieth offering to repair her roof on Monday.
The woman became suspicious and refused to allow the men to enter her home and then contacted the police.
One of the men is described as being aged 50 to 60-years-old and of stocky build.
Both of the two other men were described as being in their 20s.
The incident occurred just days after a 91-year-old woman was robbed of hundreds of pounds by a sneak-in thief in Perth.
There have also been reports of bogus workmen in the Kinross area.
A spokesman for Police Scotland’s Tayside Division: “Every year, Tayside Division receives complaints from householders who have been left out-of-pocket due to so-called workmen who vanished, leaving jobs half-done, or badly finished, typically having received a large cash sum in advance.
“With no contact details, contract, invoice or business card, the victim has no way of tracing the workmen or so-called company.
“There are also bogus callers who knock at a door – claiming to represent a company or authority – with the sole intention of conning their way in, distracting the householder and stealing from them.”
The spokesman added that people should be suspicious of anyone who turns up on their door unannounced and that visitors should only be allowed inside once their identities have been properly established.
They also advised people not to be taken in by any sales pitch given by a workman on their doorstep.
Instead, police said homeowners should resist pressure on agreeing an instant deal.
They said homeowners should take a contact telephone number to check the credentials of the person at the door and the company they claim to represent.
They should then tell the workmen that if they do want to get any work done they will call the company back
Additionally, they advise homeowners to get a number of quotes for any work that does need done to their homes and to remember that offers which appear to be too good to be true usually are.
“Never bow to pressure to pay for a job in advance no matter how demanding the workman or caller is,” added the spokesman.
“Do not allow callers to persuade you into letting them in to your home, or taking you to a bank or cash machine so you can withdraw cash for them. Never ever hand over your bank card and bank details,” added the spokesman.