A dog has been kept in a cage by police for two years without exercise, the BBC can reveal.
Stella was seized in 2014 and has been kept in a 3ft by 9ft cage in Devon ever since.
Devon and Cornwall Police refused to give specific reasons why the dog could not be exercised. They said she was considered potentially dangerous.
A worker at the kennels said they were told by police not to exercise dogs held under the Dangerous Dogs Act.
A destruction order for Stella was passed by Torquay Magistrates' Court on 8 February. Her owner was given 21 days to appeal.
Laura Khanlarian worked as an assistant at the private kennel used by Devon and Cornwall Police.
She said Stella left her kennel twice during her stay, only for behaviour assessments.
Ms Khanlarian said: "We were always told not to exercise or go into a kennel with any dogs, regardless of character, that had been brought in under the Dangerous Dogs Act.
"We were under no circumstances allowed to touch any of those dogs - which was hard.
"Animal welfare comes before anything, and that was my job. I don't believe I would be doing it properly if I would sit back and think that's OK. It wasn't OK - it's not OK."
Stella, a pit bull-type dog, was seized after police visited her owner, Antony Hastie, in Devon on an unrelated matter in 2014.
She was considered potentially dangerous because of her breed, her behaviour when police seized her and her behaviour in assessments.
Court proceedings heard from Mr Hastie, who said there were no incidents of aggressive behaviour prior to her being seized.
Evidence heard during the court case included video footage of Stella's behaviour after she had spent nearly two years locked in the kennel.
Mr Hastie attended court 11 times over Stella, but in February 2016 it was ruled she should be destroyed.
Kendal Shepherd, a vet of 30 years and animal behaviour expert, said: "It's terrible. It's unjustified. It's wasting huge amounts of money and it's not doing a single thing to prevent dog bites.
"It's cruel. But it's what our system forces us to do."
The RSPCA has created a guide to good practice for all police forces, which states: "Dogs must be provided with the opportunity to exercise away from their kennel at least once a day and this should be for a total of at least 30 minutes."
Sgt Allan Knight, from the Devon and Cornwall Police dog handling unit, said the force has released dogs back to their owners during proceedings in the past.
He added: "There will always be some dogs, for whatever reason, that cannot go back, and cannot get walked by staff because of the danger they possess.
"We are bound by the court process."
In a statement, Devon and Cornwall Police said: "In the past two years, in the region of a hundred dogs have been seized by Devon and Cornwall Police.
"During this time Stella, an illegal breed that had to be seized, has been the only dog deemed too dangerous to walk due to her aggressive behaviour.
"Once the dog was seized, an initial review was made in which the decision was reached that Stella was too dangerous to be exercised by kennel staff. This assessment remained under constant review and a number of further examinations were made by independent external experts including the RSPCA, who were all in agreeance that the animal was too dangerous for staff to exercise.
"At all times we must balance the needs of the welfare of the animal and the safety of kennel staff. The long established, licensed and accredited kennel in question was in agreement with our assessment. The dog has had continual kennel enrichment with staff and remained in fine and fit condition throughout.
"This dog has threatened and shown aggressive behaviour towards two Police Community Support Officers. There were also occasions where Stella showed aggressive behaviour prior to being seized, which were fully described in court. Stella then attempted to bite a court appointed independent expert during the dog's assessment.
"The length of this criminal case is extremely rare. None of the adjournments were requested or caused by Devon and Cornwall Police."
The full story will be shown on BBC Inside Out South West on Monday 29 February at 19:30 and will be available on BBC iPlayer.