Physical post-Brexit checks on products of animal origin are to resume at the North's ports from Wednesday.
The checks were suspended from February 1st after staff employed by the North's Department of Agriculture and by Mid and East Antrim Borough Council at Border Control Posts in Larne and Belfast were withdrawn due to concerns over their safety.
It followed the appearance of graffiti referencing increasing tensions around the Northern Ireland protocol and the post-Brexit Irish Sea border, and describing staff as "targets."
However the PSNI subsequently said there was no evidence of “credible threats.”
The department said on Tuesday it had received a full threat assessment from the PSNI and conducted its own internal risk assessment, as well as liaising with staff and unions, and checks would resume on a phased basis from Wednesday.
Staff employed by Mid and East Antrim Borough Council have already returned to work.
The Sinn Féin MLA Philip McGuigan said it was welcome that they were back at their posts, saying that “the safe return of workers is a priority and their safety must be paramount.”
However, he said there were “still serious questions to be answered by the Minister for Agriculture around how and why the staff were withdrawn in the first place and who made the decision.”
Last week, it emerged that port staff had been stood down from duty on the order of the then Minister for Agriculture, the DUP MLA Edwin Poots, who was "not convinced the PSNI had a full understanding of the risk".
The department’s most senior civil servant, Derek McMahon, told the Stormont Agriculture Committee that the Minister had been “clear in demanding that action needed to be taken to protect staff.”
SDLP MLA Matthew O’Toole said there were “clearly unanswered questions about precisely how decisions were made to stand down staff at ports last week” and has written to the Minister and the chief executive of Mid and East Antrim Borough Council seeking clarification around how and when the decision to withdraw staff was taken.
Mr Poots has been temporarily replaced as minister by his party colleague, Gordon Lyons, while he undergoes treatment for cancer.
In the North’s Assembly on Monday, the Sinn Féin MLA John O’Dowd challenged Mr Lyons on the decision, saying that “despite the PSNI’s assessment that there were no credible threats you as Minister keep referring to these threats.
“The fact of the matter is that the information given to this Assembly, and to Mid and East Antrim Council was based on half-truths, misinformation and erroneous information. Workers were used as pawns in a very, very cruel game,” Mr O’Dowd said. “The agenda of those workers being removed suits your political agenda.”
Mr Lyons rejected this, saying there “were concerns, there were threats ... the graffiti that was put up was very much taken as a threat, there were a number of concerns expressed, and it was only right that we took precautionary measures and make sure that there are additional mitigations in place.”
The actions that had been taken, he said, very clearly demonstrated that staff safety had been put first, and the process which had been put in place had been allowed to run its course. “I find that an entirely appropriate response to what has gone on,” Mr Lyons said.