"I believe that he was part of the team involved ... because as long as the Australian high commissioner was there, it meant New Zealand would be involved," Driti told New Zealand's National Radio.
"It doesn't have to be something you've got to have evidence for. It's just a matter of gauging what took place and reading between the lines," he added.
Australia and New Zealand had led efforts to prevent a coup following months of tension between the military and the elected government last year.
Last year's coup was Fiji's fourth in 20 years and was condemned by the US, Australia, Britain and New Zealand, all of whom imposed sanctions on the military government.
Helen Clark, New Zealand's prime minister, quickly rejected the charge as "nonsense".
Clark warned New Zealanders to
avoid Fiji after the expulsion
"That's complete nonsense. It's a complete fiction for them to try and level these kinds of allegations at the New Zealand high commissioner," Clark said.
"This is a disgraceful move and has no foundation whatsoever."
Canberra did not immediately respond.
Responding to Green's expulsion, she said New Zealand would lobby the UN to stop Fiji troops being used as UN peacekeepers and suspend ongoing talks with Fiji about sea boundaries.
New Zealand has refused entry to Fiji citizens linked to the military government and has cut down on ties with the South Pacific nation.