The animal charity, the USPCA, has confirmed that a number of people have had their membership terminated.
The USPCA is responsible for animal welfare
Security staff turned people who claimed to be lifelong members away from the charity's annual general meeting in Newry on Wednesday.
The society said certain people's membership ended following disputes at last year's annual general meeting.
The USPCA said the dispute was between some members and the board of the charity.
Splits in the Ulster Society for the Prevention of Cruelty to Animals emerged when the charity moved its headquarters to Bessbrook in County Armagh.
Those excluded from Wednesday's meeting said they wanted to know more about the finances of the £300,000 animal compound.
The USPCA board said it had already answered numerous questions and had set out a clear financial statement in its audited accounts.
Wednesday's annual meeting had to be suspended because there were not enough people in the room.
Stephen Philpott said the charity was not moving out of Carryduff
The society said it was keen to get on with its welfare work and avoid a damaging dispute.
However Kevin Sheehy, one of those refused entry to the meeting, said the situation was "very disheartening and depressing".
Mr Sheehy said the problems began about three years ago when the USPCA in Carryduff, outside Belfast stopped being used as the charity's headquarters.
"It meant that anyone who wanted to get a dog and house it had to go up to Portrush, which is totally ludicrous to me," he said.
A subsequent campaign over that decision caused friction.
"Our membership was terminated on the basis of our campaign," he said.
"We had to take legal action and the legal agreement between solicitors for this society and our solicitor was that we would be reinstated.
"Since then a small group of us have been anxious to make the committee accountable and give answers as how the finances are being expended in this organisation."
Mr Sheehy said the expelled members should be reinstated without qualification.
"We are not getting the answers we feel we are entitled to and the society is split down the middle," he said.
"Some of the top animal welfare people in Northern Ireland have now left this organisation because of these ongoing disputes. It is very disheartening and depressing."
The board said it had answered endless questions and the reason why some members were excluded was because of a dispute at last year's annual general meeting.
USPCA chief executive Stephen Philpott said the society was not moving out of Carryduff.
"We have one or two administrators and all we have done is move them into more comfortable surroundings," he said.
"The USPCA is not moving out of Carryduff. It has just changed the format of Carryduff. That is something that falls within my remit and something that my veterinary advisers want."
The charity said it wanted to move away from the dispute and get on with its animal welfare work.