Whanganui District Council has spent almost $30,000 assessing Midwest Ferries' proposed ferry service to Motueka.
And it could fund more "providing the information is also of benefit to the future management of the port".
Following a feasibility study which Midwest Ferries presented to councillors earlier this year a council-commissioned peer review found significant shortcomings in the proposal.
The council has been working with Midwest since to offer feedback and has so far funded three reports about the requirements for a potential large ship operation at the Whanganui Port.
The $29,809 spent includes consultants fees and $5759 in council staff costs (an estimated 160 hours).
Council special projects manager Rowan McGregor said the council would continue to assist Midwest to "better understand the opportunities, constraints and costs associated with bringing large ships into Whanganui Port".
"This information will not only support Midwest Ferries but other organisations and investors looking to bring large ships to Whanganui."
"The council is prepared to consider additional funding for expert advice for Midwest Ferries, providing the information is also of benefit to the future management of the port."
Whanganui mayor Hamish McDouall said the council was not in a joint-venture with Midwest.
"We are simply providing information with the hope that the information and advice given to Midwest may be helpful to others in a similar industry."
Midwest Ferries project director Nik Zangouropoulos said it wanted council's continued help to gather information where there is "common interest" such as dredging requirements.
"Those sorts of things would be relevant to the future of the port whatever happens," he said.
He said Midwest would likely put in a formal request for funding in the future but could not say how much.
"All I can say is it won't be a large number," he said.
"What we are trying to do is kick things to the next level."
A spokesperson for the Tasman District Council - which is at the other end of the proposed ferry link - said it had not had contact with Midwest since the Whanganui District Council's peer review.