Some police forces did not follow self-isolation rules last year due to "confusion" and fears over lack of staffing, according to a report.
Her Majesty's Inspectorate of Constabulary and Fire & Rescue Services (HMICFRS) said some forces "did not appear to follow the national requirement for self-isolating for test, track and trace".
The report blamed "confusion" over the rules and concern about the "potential adverse effect of losing resources".
"Forces sometimes saw self-isolation as unnecessary and possibly resulting in relatively large numbers of staff being told to isolate within some teams," the inspectorate said.
"Some forces therefore created their own systems to reduce self-isolation for staff not displaying symptoms, contrary to national guidance.
"We also heard about force policies where senior officers did risk assessments to circumvent the need to self-isolate.
"This was after staff told them they had received a direction from the app or the national contact tracing service to self-isolate.
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"Again, this was contrary to national guidance and, in the case of a direction from the NHS contact trace service, a criminal offence under the Health Protection (Coronavirus, Restrictions) (Self-Isolation) (England) Regulations 2020."
The report was based on an inspection carried out between March and November last year and it told police forces to "immediately" put in place policies to address the problem.
"Forces must follow the guidance and self-isolation directions when members of the workforce come into contact with someone with coronavirus symptoms," it said.
Overall, police were praised for their efforts in overseeing lockdown, especially while facing "an extremely difficult situation of fast-paced announcements" as the government regularly changed the rules.
Inspector of constabulary Matt Parr said: "Overall, the police rose to the challenge with dedication and commitment by taking immediate and decisive action to keep people safe and prevent crime, while also learning lessons from the rare occasions that they got it wrong."
Martin Hewitt, chairman of the National Police Chiefs' Council, said: "We haven't always got things right straightaway, and we have sought throughout the pandemic to learn as we go and improve the service we provide."
A Home Office spokesperson said: "The police have worked tirelessly to keep us safe during the pandemic and as this report shows, took immediate and decisive action to help protect the NHS and save lives.
"While the majority of us have been able to stay at home, our courageous officers have been out on the streets pursuing criminals, protecting the public and enforcing the coronavirus rules where necessary."
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