He was asked to comment on Tuesday's council meeting, when the QLDC decided to deal with 12 out of 19 agenda items behind closed doors.
Mr Cooper said in his time as mayor the council did as little as absolutely necessary with the public excluded.
"If more than 60% of the agenda is held without the public present, the council is not open and not transparent," he said.
"The ratepayers want to know what is going on. Clandestine meetings are now, without a doubt, clouding the council.
"If items relate to commercial matters, it can be called for to hold the meeting in secret. But they should minimise this," he said.
Crs Vanessa van Uden, Lyal Cocks and Cath Gilmour had questioned and opposed the large number of items being moved to the non-public part of the meeting.
But Deputy Mayor John S. Wilson maintained excluding the public from large part of council meetings is not a new style for the council.
"It was a coincidence so many items were of a sensitive nature at this meeting.
"I do not recall having had an agenda quite like it in my years in council," Mr Wilson told the Otago Daily Times yesterday.
He denied there was more secrecy about council dealings.
"Some might think the council is like a secret society. But that is not the case at all.
"We are representing the public, which sometimes means we will have to decide what is in the best interest of the public.
"There is no trend or new approach from the council.
"We had a new chief executive on board just months ago, and if there will be any changes, I expect it will be towards more awareness of public opinion," Mr Wilson said.
QLDC chief executive Debra Lawson, who started in the job in March, was also adamant there was no new direction towards secrecy.
"Quite the contrary. It is one of my priorities to improve the council's accountability," Ms Lawson said.
She called Tuesday's agenda "extraordinary", and said most of the non-public items were long-standing issues, which were still in a state of negotiation.
"The rules are very clear about what can or cannot be processed without public access.
"We test every item thoroughly against the legislation, and test it further during our meeting to approve the draft agenda.
"I am comfortable the items in Tuesday's agenda were handled correctly," Ms Lawson said.
Mr Wilson promised to follow up on the issue.
"I will commit to reviewing the exclusion of the 12 items with the chief executive to consider the council's future approach," he said.
