Cross-border police co-operation in Ireland is at serious risk in the event of a no-deal Brexit, new research has found.

A report published on Thursday warned that any Brexit-related disruption could have serious consequences for policing, justice and extradition.

The study, Evolving Justice Arrangements Post-Brexit, commissioned by the Joint Committee of the Irish Human Rights and Equality Commission and Northern Ireland Human Rights Commission, was carried out by academics at the University of Glasgow, the University of Strathclyde and Queen’s University Belfast.

Drawn from interviews with experts directly involved in policing and post-Brexit justice arrangements, the research found that Brexit fallback options will lead to inefficiency and ineffectiveness, bringing negative impacts and outcomes for victims and witnesses of crime.

It focuses on justice and security co-operation measures across five areas including the European Arrest Warrant (EAW), policing, prosecution co-operation, and data- sharing tools.

Despite goodwill between the two police forces, the PSNI and An Garda Siochana, the research found that legal restrictions could have an impact on operational capability, investigations and prosecutions.

For example, a current deal does not exist between the UK and Irish Governments to allow police engaged in “hot pursuit” of a suspect to cross the border.

Should Britain leave without a deal, the report also states there will be immediate consequences for the ability of the UK to participate in EU-led justice and security measures, although the EU Withdrawal Agreement does makes provision for a transitional period.

For example, European Arrest Warrants have seen high numbers of successful extraditions but, in the case of a hard Brexit, it is likely the UK will need to rely on the 1957 Convention on Extradition which then-home secretary Theresa May noted in 2014 “could undermine public safety”.

The UK’s access to systems which allow police to harvest intelligence will also be affected.

Even “with the utmost goodwill” there may be practical constraints on how closely the UK and EU27 can work together post-Brexit if they are no longer bound by the same rules, enforced by the same supranational institutions, the report warns.

Human rights organisations say any threat to north-south police co-operation must be mitigated immediately in order to preserve peace on the island of Ireland.

The report makes 13 separate recommendations for a future UK-EU security and justice relationship which also prioritises human rights protections.

Les Allamby, Chief Commissioner of the Northern Ireland Human Rights Commission, said the findings mirror what has recently been said by senior police officers in Northern Ireland.

“The new UK Government has said very little about how these issues will be managed in a no-deal situation, and how existing rights, safeguards, oversight and accountability will be maintained,” he said.

“We should not be playing fast and loose with these issues.”

Emily Logan, Chief Commissioner of the Irish Human Rights and Equality Commission, said: “While seemingly absent from public discussion on Brexit, the significance of UK-EU justice and security co-operation and the threats from it breaking down cannot be ignored considering the needs of victims of crime, witnesses of crime and the efforts of police services to safeguard people.

“This research brought forward by the Joint Committee makes it clear that, if we are to have functioning justice co-operation post-Brexit, ensuring common adherence to human rights standards is essential.”