The deaths of three cats in Hampshire are being linked to the so-called 'Croydon cat killer', thought to have killed 230 animals in Greater London.
A cat was found decapitated in Southsea, Portsmouth, on Sunday, two weeks after another was found killed in the same area, while in July, a cat was found killed on the Isle of Wight.
A Hampshire Police spokesman said: "We believe these incidents may be linked to Operation Takahe, a series of cat deaths in the Croydon/M25 area, and is being investigated by the Metropolitan Police Service."
Sergeant Tony Jeacock said: "I would like to reassure the public that we are investigating the incident and following all possible leads."
The Southsea victim, called Poppy, was killed outside a shop in Marmion Road and the cat's owner Tim Sparkes said the person responsible was becoming "more brazen".
Mr Sparkes told the Portsmouth News: "It's really about getting the message out there that this person has been around the Portsmouth area now and he appears to be doing it in clusters.
"He's becoming more brazen, usually it's not in a road, normally it's in someone's garden. It seems to be a step up in his way in killing."
The latest apparent feline victim was discovered in Croydon on Tuesday, outside a school as teachers and students returned after the Easter holidays.
Other reports over the weekend included mutilated cats killed in Chatham, Redhill and New Malden, while two fox cubs were found killed in Herne Bay.
South Norwood Animal Rescue and Liberty (Snarl), which has been cataloguing the deaths, said, from the post-mortem on the Isle of Wight cat, called Fleabags, it seemed whoever had done it had used a different weapon.
Co-founder Boudicca Rising said: "We are keeping an eye on it in case the killer was on holiday and didn't have access to their normal toolkit."
Snarl is advising London cat-owners to keep their pets indoors at night: "Our advice is not to let cats out at night, most of the deaths are happening at night."
The charity said they had received reports of 230 deaths, 40 of which were foxes, from London and as far afield as Birmingham, Manchester, Brackley and Maidstone.
The Metropolitan Police said last June that it had already spent 1,020 hours investigating the deaths since the inquiry was launched in December 2015.
In February last year, animal rights charity PETA offered a £5,000 reward to anyone providing information to police that leads to the arrest and conviction of the killer, or killers.