A council chief has faced calls to fully explain the decision to withdraw staff from Irish Sea border checks.
Mid and East Antrim chief executive Anne Donaghy declined to answer a series of questions about the controversy.
Physical inspections carried out by council staff at Larne port were suspended last week following the appearance of threatening graffiti in the seaside town and claims that car registrations had been taken down.
Former DUP minister Edwin Poots later also withdrew Department of Agriculture, Environment and Rural Affairs (Daera) staff from Larne and Belfast ports.
At a meeting of party group leaders last Monday at Mid and East Antrim council, Ms Donaghy is understood to have said the UDA was behind the threats.
Police have said there was no evidence that loyalist paramilitary groups are behind the threatening graffiti or that workers’ car registrations had been recorded.
Read more: Agriculture committee to investigate decision to withdraw staff conducting post-Brexit port checks
Council staff returned to work last Friday and Deara inspections have now also resumed, after separate threat assessments were received from police.
North Antrim Sinn Féin assembly member Philip McGuigan last night said he was concerned by a lack of information coming from the council.
"This issue is of huge public interest given the furore that has happened as a result of this action," he said.
"The safety of staff has to be uppermost but most people will be left scratching their head that both Mid and East Antrim council and DUP minister Poots ignored the assessment of the PSNI and came up with their own assessment, which now does not seem to be based in fact."
The MLA, who has also posed a series of questions to the council, said ratepayers deserve answers.
"The chief executive needs to answer Mid and East Antrim council ratepayers and citizens across the north as to how this came about," he said.
Union leaders have also said questions are not being answered around the information decisions were based on.
It is understood Ms Donaghy cancelled a meeting of party group leaders scheduled today after being told the DUP was withdrawing its participation.
In a statement in response to a series of Irish News questions, a council spokesman said its threshold for risk around staff is very low.
"Serious concerns were raised to council by a range of stakeholders, including staff, around the safety of workers at Larne Port.
"Council sought a threat assessment from the PSNI and until the level of threat, and credibility of any threat, could be determined by police, council prioritised the safety of its staff and removed them from inspection duties as a precautionary measure."
Meanwhile, DUP officials yesterday boycotted a Stormont executive committee discussion about Brexit and the Good Friday Agreement during which TDs gave evidence.
The move was linked to the party's opposition to the Northern Ireland Protocol.
Read more: Agriculture committee to investigate decision to withdraw staff conducting post-Brexit port checks
