SkyCity's renowned Gusto at the Grand has temporarily shut its doors after multiple diners reported they were ill from suspected food poisoning .
A SkyCity spokeswoman confirmed the Italian restaurant was tested for contamination after a "small number of diners" reported they suffered from food poisoning after dining there.
The tests came back negative, but multiple diners reported that they became ill after dining at the restaurant or from The Grand room service between October 11-22.
The restaurant - whose menu was designed by famed Aussie chef Sean Connolly - voluntarily closed its doors yesterday to investigate further.
Hospitality general manager Callum Mallett said the company was undertaking comprehensive precautions to identify the possible cause and the supplies, surfaces and equipment had been thoroughly tested by external providers.
Staff have been asked to undergo swab testing, but "no staff have presented with symptoms to date".
Mallett confirmed the issues at Gusto were unrelated to last week's fire at the convention centre and that there had been no recent reports of illness.
"In preparing to reopen Gusto following the fire evacuation last week, a thorough cleaning of the venue has been undertaken and new food supplies have been ordered. We are taking the additional step of testing as a precaution."
Gusto at the Grand will reopen its doors once acceptable test results are confirmed.
Mallett said he expected to reopen Gusto for breakfast on Sunday .
For guests at The Grand, room service is being provided via a separate kitchen in the main site and breakfast is being served at The Grill and Fortuna restaurants.