Zealandia wildlife sanctuary in Wellington reports its deficit has ballooned by $484,000.
The Karori Sanctuary Trust said its financial deficit for the year to June was about $1.4 million - up from $902,000 the year before.
The trust said the results were significantly better than projected as it had planned for a deficit of $2 million.
It said its financial performance actually improved significantly, but council grants fell from $700,000 in 2011 to just $40,000 this year.
About 2000 fewer people visited the sanctuary than the year before, but the trust says they spent more money.
The trust asked Wellington City Council for more money last year because of its financial position.
Earlier this year, the council pledged $1.75 million to Zealandia over the next three years as long as it was satisfied by a six-month review review of the sanctuary, which is currently taking place.
Entry price too high - Pannett
Wellington City Councillor Iona Pannett says Zealandia may need to lower its entry prices as visitor numbers dwindle.
The entry fee is $28.50 for an adult and $14.50 for a child.
Ms Pannett says she sees the current review as its final chance.
"We would have to look at bringing them in house if it just doesn't work and scaling it down. It might just need to be a conservation project rather than a tourism one as well."
But she says the sanctuary needs to be given time to put its plans into action.