The Department of Conservation says its minister, Nick Smith, never saw its full draft submission on the proposed Ruataniwha Dam in Hawke's Bay.
Dr Smith told Parliament on Tuesday he did not know about the department's submission until that very day.
DoC's deputy director, policy and regulatory services, Doris Johnston, has backed Dr Smith's version of events although an email leaked to Radio New Zealand and written by Ms Johnston says Dr Smith had asked to see the draft submission..
Ms Johnston told Checkpoint on Thursday it was true Dr Smith did not know about the submission until Tuesday.
"He never saw the draft submission that everyone's been talking about. It was never provided to his office. It was an internal working draft by department staff which then managers assessed and decided that we would not make that submission."
Ms Johnston says DoC instead decided to focus its submission only on how the dam would affect conservation land and Dr Smith had no role in making that decision.
However, she says the other environmental risks detailed in DoC's original draft submission remain.
Radio New Zealand sources say DoC staff and external advisors were devastated that the 50-page draft was not submitted and that the final submission was just two paragraphs and "neutral".
Greens call for Smith's sacking
Green Party co-leader Russel Norman said on Thursday the email showed Dr Smith clearly knew about the submission before Tuesday and he should step down for misleading the House.
"Nick Smith should resign. He is not the Minister for Conservation; he is the minister for large-scale dams; he is the minister for water pollution; he's the minister for wiping out New Zealand's native fish. He has no right to occupy the Minister of Conservation portfolio."
Dr Smith rejects that, saying the Greens are just playing politics and their claim is rubbish.
He says he saw the final submission back in July but did not see the draft until Tuesday this week after it was leaked to Radio New Zealand.
"Look, the Greens wanted DoC to make an opposing submission on the dam. The Department of Conservation decided not to and they are brassed off about that."