A man has been arrested over a string of cat mutilations in Northampton, prompting police 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 butchered to death in the town between August and November last year.
Northamptonshire Police said the suspect, who was arrested in connection to arson attacks and cat killings in the Duston and Kingsley Park areas, has since been released under investigation.
The force revealed it had been in contact with the Metropolitan Police, which continues to probe a number of animal deaths in London.
A spokeswoman said: "We are aware of the Metropolitan Police investigation, Operation Takehe, into similar offences in the London area, and we will continue to work closely with them as part of our ongoing investigation."
She added officers could not be certain if the Northampton attacks were linked to killings elsewhere in the UK but that "there are a lot of similarities".
The five cats found in Northampton all had their heads cut off and were left for their owners or members of the public to find. The dismembered body of one was dumped on its owner's doorstep and another was "deliberately mutilated" before being left on a car roof, said police.
Many of the so-called Croydon cat killer's suspected victims were also mutilated and displayed in public.
However, the co-founder of an animal rescue group which has been cataloguing hundreds of cat deaths across the UK and has been helping the police investigation said she did not think that the person arrested was behind the killings.
South Norwood Animal Rescue and Liberty (Snarl) says up to 400 cats and other small animals have been slaughtered across the country, and believes the same culprit – also dubbed the M25 killer by some – could be responsible.
But co-founder Boudicca Rising warned pet owners not to be assume their animals were safe because of the arrest.
"The killer has not been caught," she said.
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 the killings were believed to have begun in the south London area around October 2015.
But small animals, including rabbits and foxes, have since been found dead and mutilated across the country.
The Metropolitan Police has been working with the RSPCA and Snarl on the investigation, while a £10,000 reward has been offered to anyone who provides information that could lead to the arrest of the killer.
A forensics laboratory at the University of Surrey has also been re-examining the bodies of dozens of cats