Apple has squared up to the UK’s senior police officers, refusing to reduce the level of encryption on its devices, sparking a strong response from law enforcement.

Police claim they are being stifled in their duties, and that not being able to access data held on Apple devices inhibits their investigations into serious crime such as terrorism and paedophilia.

With the launch of new operating systems on both mobile and desktop devices Apple updated the privacy website that was launched a year ago.

It said: "We’re committed to using powerful encryption because you should know the data on your device and the information you share with others is protected. And we can’t unlock your device for anyone because you hold the key — your unique password."

Chief Superintendent Gavin Thomas, vice president of the Police Superintendents’ Association of England and Wales, said: "It is utterly essential for detectives and criminal investigators to use data held on smartphones and other devices when they are investigating serious crimes. Without this ability we will be seriously hindered in the types of investigations that bring the most dangerous offenders to justice, such as murder enquiries, child sexual exploitation investigations and counter-terrorism."

Thomas said that he recognises that checks and balances to protect the public’s privacy are important, he believed UK law and judicial warrants achieve this sufficiently

Emma Carr, director of the privacy group Big Brother Watch, told CBR that weakening encryption may aid the police, but it would also help cyber criminals.

Carr said: "Law enforcement can demand an individual hand over the passcode to an encrypted device. Failure to do so can result in a prison sentence. It is therefore disingenuous for the police to infer that they are unable to access any encrypted information."

Apple chief executive Tim Cook has publicly spoken about his determination to protect customer’s privacy.

The firm, whose app store suffered its first major breach recently, argues that protection for its customers would be weakened if it were to give a back door through its encryption to law enforcement.