PSNI Chief Constable Simon Byrne has said he is confident that information on police officers and staff mistakenly released in a major data breach is in the hands of dissident republicans.
At a press conference in Belfast Mr Byrne said he believed dissidents would use the information to intimidate and target police.
Last week the Police Service of Northern Ireland (PSNI) revealed a document had mistakenly been shared online which included the names of about 10,000 officers and staff.
Details released included the surname and first initial of every employee, their rank or grade, where they are based and the unit they work in.
Mr Byrne said: “I would like to confirm the picture in relation to last week’s breach continues to evolve at pace.
“We are now confident that the workforce dataset is in the hands of dissident republicans.
“It is therefore a planning assumption that they will use this list to generate fear and uncertainty as well as intimidating or targeting officers and staff.”
