Ofcom has issued a warning to consumers about a scam by bogus callers who claim to be from itself or broadband provider BT.
The UK's communications regulator claims a group of fraudsters are contacting consumers and telling them their telephone lines need digital upgrade work costing around £6 and that if it is not paid within ten days then the line will be cut off.
Ofcom and BT have alerted the police to the issue and are urging consumers not to give out any bank details to the bogus callers.
A statement from Ofcom said: "In some cases, the fraudster will claim that the line needs testing and they will temporarily disconnect it. When the consumer tries to make an outgoing call they are unable to do so.
"This is simply because the fraudster is still on the line meaning no outbound calls can be made."
Ofcom recently produced a new publication explaining broadband options to students.
It gave university-goers a simple overview of issues such as choosing fixed-line or mobile broadband and opting for contract or pay-as-you-go services.