Criminal suspects have escaped police pursuits by fleeing across the Tyrone border with the Republic of Ireland on a total of seven occasions in the past five years.
Strict rules preventing police from crossing the border allowed the suspects to evade arrest.
Criminals used the Aughnacloy Emyvale crossing, the Favour Royal Road, Augher, the Cooneen Road, Fivemiletown and the Strabane Lifford crossing, according to the latest figures.
The majority of incidents took place in the Derry-Donegal (18) and Newry-Dundalk (8) regions.
The figures, obtained from the Police Service of Northern Ireland (PSNI) by the Detail, revealed that in all 47 police chases were terminated at the border between 2011 and 2015, with all but three related to pursuits from north to south.
The information was released as governments debate how best to address the management of the Irish border in the wake of the Brexit referendum result which will see the UK leave the European Union
The figures do not take into account incidents where suspects fled before an active police chase was launched or where suspects crossed the border on foot.
The two police services indicated that they work closely and that each has the authority to arrest suspects fleeing from one jurisdiction to the other, though this does not go as far as procedures elsewhere in the European Union where police can continue pursuits across borders.
The PSNI data reveals that just 12 arrests were made in relation to six of the pursuits.
This means that in 41 of the incidents, suspects escaped without being apprehended. This equates to 87% of the total incidents.