A computer virus has forced the Greater Manchester Police (GMP) to disconnect from the UK's Police Nation Computer (PNC) system.
GMP detected the Conficker worm on the network on Friday 29 January and has cut links with the PNC until the virus is removed.
Chief constable Dave Thompson said the virus is not destructive and no data has been lost, according to the BBC.
But the GMP has been unable to carry out checks on criminals and suspect vehicles since its network was isolated.
Back-up strategy required
This case serves as a good example to organisations of the need for a back-up strategy, said Tony Speakman, regional manager for database software firm Filemaker northern Europe.
Organisations cannot take their data for granted. Disruption to data access can be costly, both in terms of time and money, he said.
The GMP has had well over a year to put the Microsoft patch in place, he said in a blog post.
Portable storage device danger
According to Cluley, it is most likely that the virus was introduced to the police systems through an infected USB stick.
Organisations should take steps to prevent unauthorised portable storage devices being connected to their networks, he said.
This would help stop the spread of malware and prevent leaks of sensitive data, said Cluley.
Organisations should be under no illusions that the Conficker problem is solved or that it no longer poses a threat, according to the Conficker Working Group (CWG), an industry group set up to combat the worm.
Not only can Conficker force networks to shut down, but the worm has enabled a robust botnet that its creators or other criminals may still use to steal sensitive information or carry out other cyber attacks, the CWG has said.