It remains unclear whether the energy department advised Australia's resources minister to veto a loan for a wind farm in far north Queensland.
Senior officials from the Department of Industry, Science, Energy and Resources are on Tuesday appearing at Senate estimates, facing questions about government spending and decisions.
The officials spent the morning answering broad questions about the government's recent $600 million cheque for a gas-fired power station in NSW, but avoided answering questions about a Queensland wind farm.
Resources Minister Keith Pitt used his ministerial veto power to stop a $280 million loan to the Kaban green power hub, which comprises a 157 megawatt wind farm.
The minister says a battery was not included in the plans he considered.
But Neoen, the company behind the hub, says it has approval for a battery with storage of up to 100MW.
The Northern Australia Infrastructure Facility recommended the project receive a loan.
Mr Pitt said the loan was against government policy.
Labor senator Nita Green has attempted to find out if senior officials told him so.
"Did the department actually provide advice to minister Pitt about the inconsistency with the government's energy policy and that project?" she said.
"The officials here have a lot of knowledge about reliability, about the energy policy, you're the owners of the so-called energy policy.
"And I'd like to know if these department officials - not the ones that will appear later - have given advice to that minister about this project."
But department boss David Fredericks said it was not the time to answer.
"The question you're asking is of the department, not of the officials. That is a question which respectfully we will answer ... next week."
He denied it was a convoluted reason.
Mr Pitt legally has to provide parliament with a statement of reasons for his decision, which he has not yet done.
A date has not been set.
Because of his decision, the Queensland government will instead help support the wind farm.