Future extradition arrangements between the North and South could be a "bit clunky" and more costly were the United Kingdom to quit the European Union but the problems should not be insurmountable, the PSNI chief constable George Hamilton said at Stormont on Tuesday.
Mr Hamilton told the House of Commons Northern Ireland Affairs committee that there would be "consequences and implications" for how extradition would work in the event of Brexit but it was best to "be careful not to talk up the consequences".
The committee is on the second of a two-day visit to Northern Ireland to hear political, security and business views about next June’s EU in-out referendum.
The committee heard the Border was 224 miles long with 292 crossing points and “more or less unfettered access” across it.
On Monday the Alliance leader David Ford warned that quitting Europe could undermine the current North-South extradition arrangements.
Mr Hamilton said the PSNI was “comfortable” working with the current extradition systems which include the use of European arrest warrants.
Over the years the system had “matured”, he said. Future arrangements, he added, “may not be just as slick; they may be a bit clunky and cost more to do”.
He said however that problems should not be insurmountable. “We do have something that is working. I would not be too pessimistic that that can’t be replaced with something else.”
“Some of the public commentary from within the broader policing community around the UK becoming a safe haven for organised criminals and terrorism, and all the rest of it, personally is not my position,” he added.
Mr Hamilton said that while in the past there had been political and constitutional problems over extradition that operationally on the ground, even going back to the days of the Royal Ulster Constabulary, relationships were good between police on both sides of the Border.
He recalled how as a sergeant in Fermanagh he had a positive working system with a Garda sergeant based across the Border in Pettigo. They operated under the same culture, he said, “to catch the bad guys”.
Mr Hamilton said there needed to be strong cooperation in order to tackle violent and other cross-Border criminality and dissident republicanism. Cooperation was very good currently between the PSNI and Garda right from the top down.
“We are in a pretty good place around that that level of cooperation and the results speak for themselves,” he said.
The chief constable said even with Brexit the quality of the relationship should not diminish. He said in such an eventuality it would be for the British and Irish governments and Brussels to set the "parameters and tone" of future North-South and UK-EU relations.
Mr Hamilton told the committee there was some evidence of illegal immigrants who had entered the Republic illegally crossing the Border into the North. There were also cases of human trafficking “but not on a scale that some would portray it to be”.
New bilateral arrangements on a wide range of policing matters would have to be agreed in the event of Brexit, the MPs were told by Mr Hamilton and Assistant Chief Constable Will Kerr, who also addressed the committee.
Mr Kerr said that borders tended to be less relevant now with international criminal gangs able to circumvent them.
“Organised crime gangs can operate largely with impunity, I have to say, in China or Eastern Europe or in the Ivory Coast and can very effectively, with almost call centre organisation, extort and bribe, particularly around sexual impropriety in many other parts of the world,” he said.