Inspectors said DNA samples were not properly stored
Cambridgeshire Police have been handed a damning report by inspectors after DNA samples were found stored in a fridge near a half-eaten takeaway meal.
The police and prison inspectorates criticised the force's custody arrangements, with overall standards described as "very weak".
Forensic samples were found to be improperly stored, cells were unsafe and officers were inadequately trained.
The force said improvements had been made and casework was not "undermined".
The inspection of eight of the force's custody suites found widespread failures to properly manage DNA material, including case evidence.
Samples were found stored alongside "unsealed foodstuffs", including frozen raw meat next to frozen congealed blood.
The situation was highly unsatisfactory, with potential failings to bring offenders to justice
The inspectors' report said: "Fridges in most suites were full of forensic samples that had not been dealt with and there was widespread evidence of systemic failings in the handling, storing and destruction of forensic and DNA samples.
"The situation was highly unsatisfactory, with potential failings to bring offenders to justice and cases being unnecessarily discontinued by the Crown Prosecution Service as a result of police failings."
The report claimed staff were not properly trained and appeared uncaring and unprofessional.
Some detainees were not fed for more than 12 hours, cells were found in a "dangerous" state of disrepair and some had "ligature points" which inmates could hang themselves from.
Deputy Chief Constable John Feavyour said he had checked every incidence of DNA storage
A swastika which was found carved into the wall of a cell was left for months and only painted over when inspectors complained to senior managers.
The inspection team also saw a group of officers laughing while watching a drunken inmate smashing his head on a cell wall on CCTV.
The report is the second to criticise DNA handling by police in the last month. In July, inspectors reported finding samples stored alongside ice-cream in a West Yorkshire Police freezer.
Dame Anne Owers, Chief Inspector of Prisons, said: "This independent inspection of the police custody suites of Cambridgeshire Constabulary exposed considerable shortfalls in many aspects of strategic management and service delivery.
"Urgent improvement was required to bring these suites up to a satisfactory standard."
Police minister David Hanson said urgent action had been taken by the force to improve "unacceptable" conditions in the cells.
Cambridgeshire Police denied its handling of forensic material had "undermined" criminal justice.
Speaking on BBC Radio 4's Today programme, Deputy Chief Constable John Feavyour said: "In relation to inadequate storage of forensic samples, clearly that was potentially serious.
"However I have undertaken an inquiry into all of those samples. In fact they were all old samples, they were all redundant and not required for any criminal cases.
"And importantly there has been no failure in any criminal justice case as a result."
He apologised "without reservation" for the carved swastika and said it was an isolated error "for which we are extremely sorry".
"The people of Cambridgeshire can be reassured that this report gives a view of how some things were nine months ago, and not how they are today," he said.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.