POLICE have warned Amersham homeowners to be on their guard after a couple were targeted by bogus window cleaners at the weekend.
The men arrived unannounced at the couple's home before contesting the amount of money they were due to be paid - having failed to complete the job properly.
They left after the couple threatened to call the police - and officers investigating the incident have told their victims to call them immediately if they spot them in the area again.
The incident happened in Station Road on Saturday at the home of a couple in their 50s.
The couple's daughter, who did not wish to be named, said: "They initially said they would charge £70 for cleaning the windows, gutters and window ledges. This then dropped to £30 for just the windows, then £20.
"This price was agreed, then in just under an hour they announced they were finished and my father placed £25 in their hand so they could get themselves a drink on him for doing what looked like a decent job.
"They then questioned the amount stating they said £70, not £20, and that they had done the guttering.
"After the men had become very rude and aggressive the police were called, oddly by both the window cleaners and my parents. On hearing that the police were to arrive they disappeared with £40, which my dad had negotiated to.
"We then assessed their work, the windows in sight were clean, anything else was smeared, the gutters undone and the ledges dirty."
The woman added: "I worry for any vulnerable older people who are not able to do their windows themselves as this was clearly a scam.
"The area I live in is full of elderly people and I think they mistakenly knocked on the door expecting someone older. I do worry that it will happen to someone who is more vulnerable."
Thames Valley Police have confirmed they are looking into the incident and have urged anyone who sees someone behaving suspiciously in the Station Road area to call them on 101.