Sir Hugh Orde, the former chief constable of the Police Service of Northern Ireland (PSNI), has said he believes border controls between north and south are "inevitable" as a matter of law.
Mr Orde, who led policing in the North between 2002 and 2009, said the symbolic nature of such a prospect should be a cause for concern.
“I would worry about post-Brexit should that legal complexity ever be unravelled, that would worry me,” he said.
“Because there are no answers yet and I would think the symbolic [aspect] – if [they] were to bring in some sort of border control which I see as inevitable simply as a matter of law rather than a matter of right or wrong – I think that puts us in a different place and I think we should be really concerned about that.”
Mr Orde was speaking in Dublin at the launch of his book Bear in Mind These Dead - The Omagh Bombing and Policing which he co-authored with Desmond Rea, the former chairman of the Northern Ireland Policing Board.
The text looks at the activities of the Royal Ulster Constabulary (RUC) in the run-up to the 1998 bombing which killed 29 people in the Co Tyrone town just three months after the ratification of the Good Friday Agreement.
Equal treatment
Earlier yesterday, Northern Ireland secretary James Brokenshire told a House of Lords select committee that the right of Irish people to live and work in Britain should not be affected by Brexit.
He said the British government stood fully behind its commitments under the Good Friday Agreement, including the right of people born in Northern Ireland to be citizens of the United Kingdom or Ireland and be treated equally in both jurisdictions.
He noted that under the 1949 Ireland Act, people born in Ireland are not treated as foreigners for the purpose of any UK law.
