Now, the Browns have removed the pond because they don't want to give the otter "another chance to kill or mutilate any more fish".
"It was devastating for us because they were so beautiful and had been a part of our life for 25 years," Mrs Brown told the paper.
"We had a good fence around the pond, a net over the top, but there is no way you could stop an otter getting in.
"Otters are cute, they really are, especially when they are lying on their backs and playing with the fish.
"But I feel the people who released these otters back into the Norfolk rivers haven't looked into this enough."