A fin spotted near a beach in Norfolk was “most likely” a basking shark, an expert has claimed. 

Matt Huw was walking along Caister beach when he saw a large fin sticking out of the water close to the shore. 

"I spoke to a local fisherman who initially thought it may be either a porbeagle, a thresher or a basking shark,” he said of the sighting on July 25.  

READ MORE: Mystery 'fin' spotted off Norfolk coast

"I'm down at the beach most days and I often spot seals, but this definitely wasn't a seal." 

Jack Renwick, a conservation officer at The Shark Trust, said: "This is most likely to be a basking shark, although it is hard to confirm from video." 

READ MORE: WATCH: Basking shark spotted off Norfolk coast

The shark species can grow up to 29ft long and are usually seen only in Cornwall and Scotland when visiting the UK. 

Another potential sighting was reported last month after a group of beachgoers spotted a fin near Cromer which was later said to be a tropical sunfish.