A determined man conjured an "incredible strength" to stop himself being swept out to sea in Suffolk as he stood in freezing water clinging on to his mother-in-law's dog.

The animal - called Ellie - jumped into the River Blyth at Walberswick, near Southwold, while the family were out for a Boxing Day walk.

Her owner's concerned son-in-law leapt 5ft down to the water, which was about 4ft deep, to rescue her.

But after finding himself 9ft from the bank, he quickly realised he was in trouble.

The Southwold lifeboat was called and the crew quickly rescued both man and dog - but spokesman Keith Meldrum said they had been very lucky,

"The tide was going out at a phenomenal rate yesterday. We'd had a flood tide and it was flowing out at a very fast rate at the narrowest point - just where he was. "Four-foot-deep water at probably about 15 knots [about 28km/h] is incredibly fast. Just the effort to stay still and hold on to the dog, never mind the concerns about the freezing water, would have required an incredible strength."

Keith Meldrum, Southwold Lifeboat,
The man jumped into the harbour at Walberswick. Credit: ITV News Anglia.

Mr Meldrum said he also spotted marks on the hands of the man's wife where he believes she had been clinging on to the rope of a lifebuoy for up to half an hour to stop him being washed out to sea.

The man, called Colin, was taken to the James Paget Hospital by ambulance where he was treated for extreme cold.

Ellie was cared for by the lifeboat crew who spent 40 minutes cuddling her to help her warm up. Both recovered.

Mr Meldrum said dog rescues at Southwold Harbour were a regular task for the crew - but urged people not to jump in after their pets.

"We have calls to dogs in the harbour relatively frequently - it's almost a light-hearted thing, another dog in the harbour. "But when someone has gone in to rescue their dog, they always get into trouble. This is the second time this year someone has got into trouble trying to recover their dog. "If it's just a dog, we get in and recover it. There's never any fuss, no trouble at all. Once someone has gone in it always becomes much more serious."

Keith Meldrum, RNLI Southwold.