Some television viewers in Kent have had their programmes blacked out without warning.

Transmission changes to the Freeview transmitter at Blue Bell Hill led to several types of set-top boxes being unable to pick up the new signal.

It means viewers will now need to replace their equipment to continue receiving the Freeview service.

The boxes affected are the Daewoo DS608P, Labgear DTT100, Triax DVB 2000T, and Portland DP100. The combined set-top box and video recorders affected are the Daewoo SV900 and Bush IDVCR01.

Rob Farmer, Freeview marketing and communications director, said: "We appreciate the frustration of viewers, it’s a minority who have been affected by these enhancements.

"DMOL – the company that runs the engineering behind Freeview – completed the technical changes for the UK at the beginning of August and to date we’ve received a total of 2,300 calls (across the country).

"The boxes affected were manufactured four to five years ago and are pre-digital tick.

"Together with the manufacturers we’re doing all we can to help viewers find the best value replacement."

When Freeview launched in 2002, there were about 30 TV channels.

It now offers up to 48 TV channels plus digital radio stations.