Shearer said it was important not to over-react and Bainimarama should be free to make a visit to watch the rugby. However, a formal 'state' visit should be delayed until the situation cleared.
"While we should not overstate what has happened nor should we sit back and say everything is perfectly normal because it clearly is not.
"I think it would be probably a good idea to just quietly put the state visit on hold for a while.
"I just don't believe right now that Prime Minister Bainimarama quite understands what democracy is all about."
After the incidents in Fiji over the weekend, Foreign Minister Murray McCully told the Fijian Government New Zealand was taking a "close interest" and voiced concern about freedom of political expression.
The European Union Delegation for the Pacific has also raised concerns, urging "full respect for freedom of speech and freedom of assembly in Fiji".
Those taken into custody were National Federation Party leader Biman Prasad and Sodelpa leader Sitiveni Rabuka - a former Prime Minister and coup leader.
The others were head of the Fiji Council of Trade Unions Attar Singh, former politician Tupeni Baba and civil society advocate Jone Dakavula. Labour Party leader Mahendra Chaudhry had also handed himself in and been questioned.
It came in the same week Bainimarama again snubbed the Pacific Islands Forum meeting because of his objections to New Zealand and Australia taking part.
On the same weekend, Fiji also announced it was pulling out of the Pacific-wide Pacer Plus trade negotiations because of concerns about Australia and New Zealand.
That was on the eve of a visit to Fiji by Trade Minister Todd McClay, who has now called off his trip.
Shearer said in the space of a few days Opposition leaders had been jailed, Bainimarama had appointed himself Foreign Affairs Minister in a Cabinet reshuffle and Fiji had withdrawn from Pacer Plus.
"That seems to me to be more Bainimarama saying 'I'm in charge here. I make the decisions'."
Bainimarama visited New Zealand in 2014 to campaign for expat Fijian voters living in New Zealand but has not visited in his capacity as Fiji's Prime Minister.