POLICE are warning North-East businesses to beware of a re-emerging trend where their telephone exchange systems are vulnerable to exploitation. The fraudsters target the telephone system and then use them to make a high volume of international premium rate calls, raking in thousands of pounds.

Cases of this nature came to light in 2014 and towards the end of 2015 - and this year North-East businesses have again become victim to this type of fraud.

The scam is most likely to occur when businesses are closed but their telephone systems are not.

DC Jonathan Stoker, from Durham Constabulary cyber crime team, said: “The businesses affected have lost a lot of money and some have ended up with bills running into thousands of pounds.

“The police are investigating the sources of the hacking but in the present day and age this could be from anywhere in the world. We are currently working with the businesses to unravel the layers to get to the source of the hacking.”

The National Fraud Investigation Bureau (NFIB) is advising businesses to use strong pin/passwords for voicemail systems.

Firms should also disable access to voicemail system from outside lines.

If staff do not need to call international or premium rate numbers, businesses should ask their telecoms provider to place a restriction on their telephone line.

To report a fraud call Action Fraud on 0300 123 2040 or visit the Action Fraud website.