A marksman was hired to shoot a fox at a cricket ground.
Residents living near Sussex County Cricket Club in Eaton Road, Hove, called police after hearing shots in the early hours of Sunday.
Officers later told them that a licensed gun was being used to exterminate foxes.
Club bosses said they had called in a pest control expert after persistent problems with one fox.
But animal lovers have reacted with anger at the killing.
Nigel Furness, 60, was at The Sussex Cricketer pub in Hove when he heard three shots just after midnight.
He said: “I thought, ‘there’s something wrong here, what on earth is going on?’ “It’s a big open space so it can be quite creepy at night.
“Then about five minutes later a police car came up. I asked the officers what was going on and they said there’s nothing to worry about, the cricket club is just shooting foxes and it is all legitimate.
“But there really is no need to shoot foxes. They are completely harmless and destroy a great many pests like slugs and snails and we are absolutely appalled.
“It is also extremely alarming that we were never told what was going on.”
Dave Brooks, the club’s chief executive, said: “We have had foxes frequently on the ground for many years but this particular one over the last few months has started to cause problems by scratching around on covers and acting oddly. It was probably not particularly healthy because of its behaviour.
“We went through all of the different processes we could consider, such as rehousing it, but we were told that we were not allowed to do that, so the only alternative we had left was to have the fox killed by a licensed company.
“We really didn’t want to do it but it was a last resort. We have never had to go to these lengths before and we hope we won’t have to do it again.
“Foxes have been here for many years and I am sure they will continue to be here for many years to come.”