An unexplained distress signal from an emergency radio beacon sparked an extensive early morning search from rescue crews.

A RNLI lifeboat, coastguards and a helicopter were involved in the search off the East Anglian coast for more than four hours on Sunday morning (March 12).

The volunteer Lowestoft lifeboat crew were the first to be alerted in the early hours when a distress signal was picked up from an Emergency Position Indicating Radio Beacon (EPIRB) by a satellite and detected by a monitoring station in the west country.

Lowestoft Lifeboat coxswain John Fox said: "We were called out at 1am to search an area eight miles east of the town for the beacon which is activated in emergencies to indicate a vessel in distress.

"Lowestoft Lifeboat Patsy Knight was launched but there was no obvious vessel or person in need of help when we arrived - so we started an 'expanding square' search pattern – widening the search area from Covehithe to Hopton.

"After looking for two-and-a-half hours in choppy conditions using our direction-finding equipment and locating nothing – we returned to Lowestoft to await the arrival of a Coastguard helicopter from Humberside which had been sent to help."

Mr Fox added: "From an unobstructed vantage point in the air, they picked up the signal in Lake Lothing.

"We went through the bridge to where they indicated that the signal came from and with the help of the Lowestoft Coastguard Rescue Team located the beacon, which also has a flashing light when activated, on an old vessel that was out of the water on the quayside at a Marina.

"The satellite calculates the position of the beacon.

"They are good but not exact and so we use our direction finder to try to pinpoint the source - although in this case it turned out to be a false alarm."