Fresh sightings of dead seals and porpoises on Happisburgh and Great Yarmouth beaches have raised concern over what could be lurking off the Norfolk coast.

Eastern Daily Press: Great Yarmouth: 7.45am. Wednesday February 15. Picture: Elvis MastersonGreat Yarmouth: 7.45am. Wednesday February 15. Picture: Elvis Masterson (Image: Archant)

It's been speculated that the seals could have been killed by boat propellers but these new pictures appear to show 'tooth marks' on the carcases washed up on the sand.

Sighting 1: Elvis Masterson, 37

Location: Great Yarmouth

Date and time: Wednesday, February 15, 7.45am

'I found what I believe to be a porpoise washed up on Great Yarmouth beach on my morning dog walk between the beach hut and the coffee shack cafe - level with the waterways.

'On first seeing the animal I assumed it was another seal carcass, as I'd seen half of one only a couple of weeks before. As I started to approach, I realised it wasn't a seal as I noticed its tail and fins.

'Now I was more curious as to what it actually was - thinking dolphin, porpoise, or maybe infant whale. As I got close to take a second picture to try and determine what it was I saw that half its face was missing from what looked like it could be bite marks and something had mauled it.'

Eastern Daily Press: Happisburgh: 12.00pm, Wednesday, February 15 Picture: Chloe Baker-CooperHappisburgh: 12.00pm, Wednesday, February 15 Picture: Chloe Baker-Cooper (Image: Archant)

Sighting 2: Chloe Baker-Cooper, 19

Location: Happisburgh

Date and time: Wednesday, February 15, 12pm

'I was with my boyfriend and we'd walked from my house in Stalham to Eccles on Sea then across the beach to Happisburgh and found this just as we got there.

'It looked like it had been half eaten, and had tooth marks in the site of it too - you can see them in the picture.

'We thought it might be a porpoise, but we're not experts!'

MORE: What is killing the seals? Carcass split in half found on Waxham beachSighting 3: Sue Stephenson-Martin, 45

Eastern Daily Press: Happisburgh: 2.30pm Sunday, February 19. Picture: Sue Stephenson-MartinHappisburgh: 2.30pm Sunday, February 19. Picture: Sue Stephenson-Martin (Image: Archant)

Location: Happisburgh

Date and time: Sunday, February 19, 2.30pm

'It was on the beach at Happisburgh behind the flood defences. I almost stood on it as I was taking a photo.

'I was a bit shocked as I didn't expect it, but had seen the previous reports.'

MORE: Cannibal seals killed dozens of north Norfolk seal pups, say scientists after five-year investigationWhat do you think is responsible for the deaths? Let us know in the comments.