Loading Victoria's chief health officer Dr Brett Sutton on Tuesday said it was "a pretty dramatic food-borne outbreak". "In the fashion of a true food-borne mystery, it was the relish in the Olympic Room at high noon on Anzac Day," Dr Sutton said. It made at least 38 people sick, including one staff member, some of whom fell ill so quickly paramedics assessed them at the MCG. Seven people at the $725-a-head lunch were taken to hospital. They were treated in emergency and discharged.

People who ate the relish were 12 times as likely to have fallen ill than those who did not. "The conclusion is that the relish is likely to blame. I know that there was a lot of talk about the terrine initially and in fact a lot of people ate the terrine as well as the relish so it was very hard to separate those," Dr Sutton said. "But in the course of interviewing over 100 people, it's been identified that the relish is almost certainly the cause of this outbreak." Most likely, one of the ingredients carried a toxin that was not killed by boiling water used to make the relish. That batch of barberries was examined, though no issue with them was found, and they were later destroyed as a precaution.

The health department remade the relish over and over to try to identify the issue. "We recreated the relish under a whole bunch of different conditions - [using] dehydrated barberries, barberries with boiling water, the relish refrigerated for three days, the relish left out - none of it allowed sufficient growth of bacteria that would have caused that illness. "So even though the relish was probably the vehicle for the illness, we don't know exactly what it was." The relish was quite acidic, Dr Sutton said, and did not have the conditions they expected to harbour contaminants. It seemed to be "just pure bad luck". It was most likely a toxin to blame - as opposed to a virus or bacteria, which could cause salmonella - given guests had such a quick reaction. Some people fell ill within half an hour.

Loading Lydia Buchtmann from the Food Safety Information Council said this was a particularly rare and unlikely case. "Really, any food can be contaminated with food poisoning bacteria." The department interviewed 109 guests and staff who worked at the function, and no specimens were collected from the patients. Melbourne City Council health officers also inspected the venue but no issues were found.

Collingwood president Eddie McGuire had said people were "going down left, right and centre" during the national anthem. "It was an amazing situation because people were literally, during the speeches, dropping like flies around us," McGuire said at the time. "In fact at one point you could see people in the minute of silence trying to stand up and then when it got to the national anthem people were going down left, right and centre, so we were wondering what was going on." Guests reported watching others collapse in the hours after the terrine entree was served about 12.30pm. Some people fell ill during the Anzac observance ceremony about 3.30pm. The Melbourne Cricket Club (MCC) and caterers EPICURE accepted the inconclusive outcome.

"The MCC and EPICURE have always and will continue to strictly comply and exceed industry best practice in relation to the handling of food items and service," a joint statement said. "Additional precautionary measures have been implemented and food items associated with the function's entree have not been served at the MCG since the incident, including the suspected item identified by the DHHS as the most likely source of illness." The MCC and caterers stressed safety and quality of service was of the utmost importance. "We are deeply disappointed that this incident occurred and express our sincerest apologies to those patrons affected on Anzac Day."