Councillors were not invited to the function at the Municipal Theatre.
Napier Mayor Kirsten Wise said she was not even aware of the farewell party until made aware of the spending in the audit report by RNZ.
"It was a little bit of a surprise to me ... and it is disappointing that none of the elected members were invited."
While Wise had initial concerns about whether the spending had been signed off appropriately, she had since confirmed that "all the correct delegation processes were followed".
"I was advised it was based on a full complement of staff being at the morning tea shout, and at a cost of $6.50 per head ... I wouldn't say it's excessive. But I'm unaware of how many staff members turned up."
A Napier City Council spokesperson said the event was "very well attended".
"It was considered appropriate to invite all staff [approximately 660] given his length of service in his role as chief executive. Mr Jack had been in the role for seven years since his appointment in 2013."
He was also presented with a $600 patu pounamu for his service.
"Council does not normally provide gifts for leaving staff members (which are normally funded by contributions by staff), but due to the short departure time frame, and given his length of service, a gift of a patu pounamu that cost around $600 felt appropriate," the spokesperson said.
"While it is not normal practice to provide catering at council events, due to the nature of this event, catering was again considered appropriate."
A copy of the council's sensitive expenditure policy, included in the same agenda, noted farewell functions were not to be "extravagant".
"Expenditure on farewells, long service and retirement includes spending on functions, gifts and other items, and should not be extravagant, or inappropriate to the occasion," it said.
