A no-deal Brexit could have a “serious effect” on the ability of the police to fight crime, a watchdog has warned.
Biometrics commissioner Paul Wiles raised the concerns in his annual report which was submitted to Parliament on Thursday.
In it, he said: “The last year has been dominated by concern about the possible effects of Brexit on European exchanges and cooperation.
“If, in the event, the UK is excluded from the main exchange mechanisms, that would have a serious effect on the police ability to deal with inter-country and international criminality.
“The police have been working on mitigation planning but this will not remove the risks involved.”
He said EU exchanges would be “continued as part of a Brexit deal or, if we leave without a deal, they will cease.”
Mr Wiles also questioned whether new rules for the use of fingerprints and DNA were stalling because ministers were focusing on Brexit instead.
In the report, he said: “Home Office ministers currently show no sign of proposing a new legislative framework with specific rules to govern the police use of new biometrics in England and Wales.
“I do not know whether this is because they disagree with the need for such legislation or whether this is just another casualty of the need to focus on Brexit matters.”
As part of his findings, he continued to criticise the Home Office, saying changes in policing had “unintended consequences” in the use of fingerprints and DNA.
He added: “The overall result has been a decline in the number of new suspect DNA profiles and fingerprints being added to the national DNA and fingerprint databases, which will lead to a long-term decline in the utility of police biometrics.
“A general theme behind these issues has been the inability of the Home Office to predict the consequences of its actions. Further, the problems that have arisen have been exacerbated by the fact that neither the Home Office and nor the police service have promptly provided practical guidance to mitigate these consequences.”
Mr Wiles said there was also “clear urgency” in addressing concerns he had that the Ministry of Defence (MoD) was using police fingerprint records unlawfully.
He said: “I continue to be very concerned about the searching by the Ministry of Defence into the police national fingerprint database without an agreed, clearly defined lawful basis.
“I hope that the National Police Chiefs’ Council will resolve this issue in the near future and I shall report the outcome. It should be noted that this relates to my point above that inter-government searching of databases should be properly regulated.”
He also urged rules to be introduced preventing police misuse of facial recognition in public places.
He said: “At its extreme it is raising the spectre of using facial scanning for mass police surveillance.
“That may be unlikely but one that some countries are reported as developing.
“The sober point is that unless there are clear and publicly accepted rules governing the police use of new biometrics then damage could be done to public trust in policing and at a time when regard for some other public institutions is declining.”
Referring to the legal case brought by civil liberties group Liberty against South Wales Police for its trial of the programme, Mr Wiles said the awaited judgment on the matter would be “significant” for all police forces.
A Home Office spokeswoman said: “We support police use of biometrics and other new technologies to help protect the public and bring criminals to justice, but it is essential that they do so to high standards and maintain public trust.
“We welcome the Biometrics Commissioner’s Annual Report on the work he has done over the last year to promote compliance with the rules on the use of fingerprints and DNA, which we have published in full.
“The Home Office has established a new board to oversee the police use of facial images and other new biometrics, and the Minister for Policing and Fire will shortly provide an update on options to simplify and extend biometrics governance, aimed at maintaining the right balance between public protection and privacy.”