The union owes the council $399,464. A council spokeswoman, who confirmed money for ground rental was outstanding, said she knew nothing of the grant in question.
Grant recipients are required to present proof of purchase receipts as trusts audited annually by the Department of Internal Affairs.
A department spokesman said trusts were responsible for ensuring recipients spent their grant money according to their application.
"We have not been advised by any trust of an issue with ORFU grants, but we would follow up any concerns that are reported to us, or arise in the course of our audits. A trust must use its best endeavours to recover money not used for the specific purpose it was granted."
Otago Rugby Union change manager Jeremy Curragh said the union was "going through a complicated financial reconciliation process where the amounts owing to creditors and the circumstances around debts are being verified".
"We can confirm that some of the creditors relate to costs that have been funded by trusts. We have talked to these trusts."
Warwick Hodder, general manager of the Trusts Community Foundation, a leading supporter of the union, said the group was awaiting receipts for $286,000, money granted last year for the purpose of amateur rugby.
"In January, we indicated that we wouldn't give any more grants until we got accountabilities for the stuff we had already supported," he said.
"I am expecting when we do the final wash-up with them that a lot of it would have been paid, because we have certainly had no [other] indication since they announced their position."
The trust had not been kept up to date about the union's position, Mr Hodder said, and "it is fair to say we are disappointed that it has taken this long to account for [the grants]".
- Otago Daily Times