Volunteers have reaffirmed their dedication to watching the Norfolk coast after it emerged Dutch police had intercepted a boat carrying Vietnamese and Albanian migrants - which was thought to be bound for Sea Palling.

Members of the National Coastwatch Institute at Gorleston and Caister work to train, watch and listen for radio distress calls along the coastal waters and beaches, recording all movements of vessels and people.

They are the unseen eyes and ears co-ordinating with the Coastguard at Humber, and all work voluntarily.

Linda Lawrence, station manager at Caister, said the National Coastwatch Institute was a significant part of the national search and rescue service.

Among its duties, search and rescue teams may be called out if a suspected smugglers' vessel gets into trouble at sea.

Mrs Lawrence said: 'We provide a watchful pair of eyes and timely exchange of accurate information, prior to and during any search and rescue operation both along the coastline and offshore.

'I've liaised with the Border Force, and all our watchkeepers are very aware of the growing problem of the attempted landing of illegal immigrants, including the recent incident of Sea Palling, where a map of the Norfolk coast was found.'

Barbara Hay, station manager at Gorleston, said: 'We watch all movement and everything gets logged and reported to the correct authority if necessary.'

The importance of agencies - both governmental and voluntary - working together was highlighted earlier in the week.

When news emerged that just three small boats called cutters, all based at Portsmouth, monitor the security of 7,700 miles of British coast. In comparison Italy has more than 600 such boats and France 40.

But from May 31 new powers came into force to help target smugglers and prevent illegal entry.

These will allow Border Force officers to stop, board, divert and detain vessels and arrest anyone they suspect has broken immigration law.