Napier City Council is in the process of commissioning a review, which it says will establish how the storage issue arose and exactly what the shortfall of space is.
Hastings Mayor Lawrence Yule, whose council contributed $1 million to the project, said yesterday he had discussed the issue informally with his councillors and they wanted to know what had changed and how the storage issue could be resolved.
Mr Yule said the initial feasibility study for the facility indicated storage space on the site would increase from 300 sq m to 453 sq m.
"Now for whatever reason that's changed along the way and I think what people want to know is what has changed and then, once we know that, what can actually be done about it."
The MTG issue was also raised at a meeting of the Hawke's Bay Regional Council's environment and services committee this week.
Councillor Tom Belford asked chief executive Liz Lambert if the council should be concerned about the $2.5 million it had contributed to the facility. Ms Lambert said the regional council would be in a better position to assess the situation after the Napier City Council review was completed.
Councillor Rick Barker asked for staff to review the paperwork related to the contribution so it was clear if any conditions were attached to the funding, and if so, whether they had been met.
But other councillors did not see the need to act on the issue until after the results of the Napier review were known. Alan Dick said the issue "seems to me to be a stoush for the sake of a stoush" and Christine Scott said the council should be mindful of not acting on hearsay.
In a statement released after a meeting of the Museums Trust this week, trustees said they believed the storage and care of the collection "meets very high levels".
"Over the last few years the packaging of the collection has been upgraded to meet museum standards for disaster planning and risk management particularly as it relates to earthquakes.
"As a consequence of this higher level of protection the bulk of the collection has increased."
The trust's collections had also grown since the museum was closed for renovations in 2010, contributing to the storage issue.
"Parts of the collection were never intended to be stored in the new MTG building."
But Mr Yule said the original proposal had been to store the entire collection on one site and he was unsure why earthquake protection was an issue given the MTG building was 100 per cent earthquake compliant.
A Napier City Council spokeswoman said the council hoped to finalise the terms of reference and the contractor who would carry out the MTG review next week.
The result of the review was expected in mid-April.
The council has previously said that as well as looking at the storage issue, the review would examine the museum's $15 entry charge and why exaggerated forecast visitor number figures for the facility were included in council planning documents.