Disclosure of the Governor-General's "extravagant" spending of $3.5 million on everything from flowers to functions has provoked demands for an official inquiry.

Details of spending show Sir Anand Satyanand gets a large personal allowance to host events around New Zealand - and spending on individual items includes about $27,000 a year on floral arrangements.

The total cost from the budget of the Department of Prime Minister and Cabinet shows the Governor-General and maintenance of Government Houses in Auckland and Wellington cost about $3.5 million.

DPMC corporate services manager Brent Anderson said: "He's an incredibly busy man, he's incredibly energetic. He attends and hosts a large number of functions."

The cost of the Governor-General has been under scrutiny after $45m was spent refurbishing Government House, which has just reopened.

Republican Movement chairman Lewis Holden said there needed to be a clear review of the "extravagant" spending by the Queen's representative.

"He's not the monarch. He's the Queen's representative. But he's spending money like it was his face printed on the notes."

But Monarchist League chairman Simon O'Connor said the $3.5m was a reasonable expense. "The Governor-General ... is doing it on behalf of all New Zealanders - we get a really good deal."