A coastguard emergency radio channel was blocked for 12 hours by a sailor off the coast of Shetland listening to BBC Radio 4 non-stop.  

Shetland Coastguard had to contact the BBC for help after a ship somewhere near the islands accidentally broadcast the station on to the maritime emergency channel.  

Radio 4 had to send out a message telling all ships in the area to check their radio equipment. It is though the channel had been left open by someone leaving the broadcast switch on.  

The distress and safety frequency, known as VHF channel 16, experienced intermittent interference on February 5 as the sailor listened to episodes of The Archers, Woman's Hour and Just a Minute. 

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The Radio 4 message said: "This is an important safety related message on behalf of His Majesty's Coastguard. 

"This radio programme is being transmitted over VHF channel 16 by a vessel with an open mic. 

"This is blocking all distress, urgency and safety broadcasts. 

"All vessels in the vicinity of south east Shetland are requested to check their radios and ensure that the microphone transmit button is not being inadvertently held open." 

The Herald: Boats in Lerwick Harbour, Shetland Boats in Lerwick Harbour, Shetland (Image: PA)

Laura Kay, the team leader of Shetland Coastguard, told Radio 4's Broadcasting House programme how the incident unfolded. 

She said: "The day watch had Radio 4 coming through the transmission. It was transmitting for about 12 hours at various levels of clarity. 

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"In our policy there is actually a bit that says 'If you can hear a radio station, you can contact them and ask them to broadcast a safety message'. 

"We have had incidents before where there has been a fault with the equipment. 

"If you spilled something on the handset the button could stick or it's just not been properly set down." 

The Herald: HM Coastguard HM Coastguard (Image: PA)

The team leader added that there had been no "incidents" during the period the channel was blocked. 

The Coastguard said VHF Channel 16 "must be kept clear for distress and urgency traffic only" and urged mariners to regularly check their radio equipment to ensure that it is in good condition to avoid accidental transmissions.