A man has been arrested over a string of cat killings in Northampton as police continue to investigate whether the attacks are linked to the so-called Croydon cat killer.
The 31-year-old was held after five cats were found dead and mutilated in the town between August and November last year.
Northamptonshire Police said the suspect, who was arrested in connection with arson attacks and cat mutilations in the Duston and Kingsley Park areas, has been released under investigation.
The force confirmed it is working closely with the Metropolitan Police probe into a number of animal deaths, known as Operation Takahe.
But it said that although the offences are similar to attacks in the London area, officers cannot be sure they were carried out by the same person.
The co-founder of a group which has been cataloguing the deaths and helping police with the investigation has said it does not believe that the person arrested was behind the killings.
South Norwood Animal Rescue and Liberty (Snarl) believes up to 400 cats and other small animals may have been slaughtered across the country by at least one culprit, who has also been dubbed the M25 cat killer and the UK animal killer.
Snarl co-founder Boudicca Rising is warning pet owners their animals are still not safe as she told the Press Association: "The killer has not been caught."
Her comments come following a string of reported attacks over the festive period in south London, north London, Aylesbury in Buckinghamshire, and Tunbridge Wells in Kent.
Ms Rising believes the most recent cat deaths could hold the key to catching the killer.
"What is really clear from the timeline over Christmas is that he was in south London and then started travelling again," she said.
"We have always thought he is a south London resident.
"He seemed at ease with getting around and the killings seemed more confident."
The attacker was first dubbed the Croydon cat killer, because it is believed the killings started in the south London area in around October 2015.
But small animals, including rabbits and foxes, have since been found dead and mutilated across the country.
The Met has been working with the RSPCA and Snarl, while a £10,000 reward has been offered to anyone who provides information that could lead to the arrest of the killer.