Astonishing footage shows a greedy otter sneak into a retired teacher’s garden pond – before devouring more than 100 Koi Carp. Kieran McCarthy, 68, was shocked when his beloved fish – worth thousands of pounds – began vanishing. He suspected an otter was to blame after he found the stripped-down carcass of a fish dumped by the side of one of his two ponds. Despite splashing out £140 on chicken wire which he covered over the top of the pond in his back garden, the otter still forced his way in and killed dozens of fish. Over the course of just five days, the otter slaughtered 106 of Kieran’s expensive Koi Carp - which are worth around £7,000 - leaving the retired teacher fuming. Kieran, who has five grown-up children and seven grandchildren, said: “I’ve been looking after fish for 25 years but I've never seen anything like this before. "I'm cheesed off, angry and frustrated but an otter does what an otter does. "I have spent £140 on chicken wire and I spent all day in the pouring rain securing the back pond. "I keep two ponds, one in the back garden and another at the front. "It was all about the otter, no matter the cost to its victims or me." The nuisance otter first struck at Kieran’s suburban home in St Johns, Worcester, on October 20. He added: "I couldn't believe that in a built-up area, we would see an otter-like this. "It has been six consecutive nights and you can't relocate otters because they are protected species. "But it's hard to see the fish's throats being slashed or getting infected. "The otters keep finding a way in, they are very intelligent creatures. "It's caused absolute havoc and I know I can't get rid of them. "The council told me I was lucky to have otters in my garden. "But when you have fish, they are absolute killing machines. "I've been shooing it away with my torch, but one night it didn't work, he looked me in the eye and carried on. "He is so brave. "He comes into the garden between 8.30pm and 5am. "He doesn't follow a schedule or a set diet. "I have had pet fish for years and they're hard work and they are very expensive to keep. I can't go through all of this again. "It has been a hobby for years "I can't go out to spend that type of money. "It's just soul-destroying, I don't blame the otters, what they are doing is part of nature. "One fish has become infected and it will spread. "I'm going to have to find something else to do now." Kieran has had most of his fish since they were minnows. Koi can be some of the most expensive fish in the world with some fetching up to £2,500 each.