People walk away from the entrance of the European Court of Justice in Luxembourg | John Thys/AFP via Getty Images European Arrest Warrants apply until Brexit date, says ECJ Court finds that EU members must cooperate with UK authorities until official Brexit date.

An EU member can't suspend cooperation with U.K. authorities on a European Arrest Warrant on the grounds that Britain is leaving the bloc, the EU's highest court ruled Wednesday.

"Mere notification by a Member State of its intention to withdraw from the European Union is not an ‘exceptional’ circumstance capable of justifying a refusal to execute an EAW issued by that Member State," the European Court of Justice said in a statement.

The ruling relates to a case in which a suspect arrested in Ireland in 2016 on the basis of a European Arrest Warrant issued by the U.K., claimed he could not be extradited in light of issues related to Brexit. The Irish court deferred to the ECJ on whether it is "required to refuse to surrender to the United Kingdom a person subject to an EAW whose surrender would otherwise be mandatory."

The ECJ found that Britain's notification of its intention to withdraw from the bloc by triggering Article 50 "does not have the effect of suspending the application of EU law in that Member State," and as a result "the principles of mutual trust and mutual recognition" would "continue in full force and effect in that State until the time of its actual withdrawal from the EU."

It added that although the executing judicial authority has to examine whether there are "substantial grounds" to believe that the person subject to a European Arrest Warrant is "at risk of being deprived of his fundamental rights" after the issuing country's withdrawal from the bloc, it should "presume" that the country will continue to apply those rights unless there is "concrete evidence to the contrary."

"In the view of the Court, such evidence does not appear to exist," it said.