officers in an attempt to stop rising numbers being scammed.
Police, who are patrolling areas in the town where reports have come from, have urged pensioners to be aware of criminals requesting money for fake services following a recent spike - which has included criminals acting as a group in order to gain entry.
Bogus officials have claimed to work for Barnsley Council, the NHS and other official organisations in order to gain entry.
In recent cases, they have claimed they have spotted urgent property repairs that need to be carried out..
A police spokesman said: “There has been an increase in reports of unwanted and suspicious persons attending people’s doors late at night, canvassing for business.
“It would appear that the elderly, and vulnerable, are the ones being targeted.
“We would advise residents to be vigilant when answering their door.”
Police in Barnsley have handed out stickers to residents, which can be placed in windows, displaying a sign which warns unwanted callers not to try their luck.
Fraud officer Andy Foster, who deals with financial-related matters for the police, said: “Police identified an emerging theme within the Barnsley area.
“One of the incidents involved a female who was knocking on the doors of older people stating she had done work on the occupier’s guttering and required payment.
“We believe the same female has also used the excuse of her vehicle having broken down, also asking for money.
“The same suspect has emerged using similar excuses calling on residents within the Barnsley area, although in this case the suspect is not purporting to be from an official body.”
According to South Yorkshire Police, offenders have also been tricking their way into people’s homes to steal money or valuable items - a method known as a distraction burglary - by showing fake identification.
Official Barnsley-wide figures show burglaries were reduced in February and March, following a marked rise throughout 2018.
A spokesperson from the police added: “Offenders may make themselves seem genuine and friendly at the front door, keeping people distracted while their partner manages to get into the home.
“People should never give money to bogus officials - employees of official organisations would never ask for cash or bank details.
“Always ask to see the identification badge of anybody attending your home. Employees from official companies will always be happy and able to provide one.
“Keep an eye out on neighbours as vulnerable, elderly and
isolated people are often targeted, while Barnsley’s neighbourhood policing teams can be contacted to raise any concerns.
“If you do believe you have been approached by a bogus caller, report the details via 101.”