Calombaris’ Hellenic Republic in Kew is being investigated by the Department of Health and the local council, after reports that at least two groups of diners fell sick on Sunday evening.

It is understood the alleged victims consumed items from a set menu designed for Mother’s Day – a day that saw 600 diners through its doors – with most suffering from vomiting, diarrhoea and stomach cramps.

‘‘It’s completely put us through the wringer,’’ said a victim who asked not to be named. ‘‘My wife was vomiting all day yesterday and most of Sunday night. This stuff shouldn’t happen at a restaurant like this.’’

Boroondara Council community development director Carolyn McClean confirmed complaints of a ‘‘gastroenteritis outbreak’’ had been received.

‘‘An inspection of the premises was conducted by a council environmental health officer on Tuesday evening to obtain food samples and to ensure that appropriate infection control practices had been implemented,’’ Ms McClean said.

‘‘Faecal specimen collection kits have also been delivered to a number of the affected people to assist in investigating the outbreak.’’

A Department of Health spokesman said they were notified on Tuesday afternoon and were awaiting sample results before a cause could be determined.The spokesman urged anyone who had fallen ill after eating at the Cotham Road restaurant on Sunday to seek medical attention.

A spokeswoman for Calombaris’ company, Made Establishment, said there was ‘‘no evidence as to the cause of this’’, but the restaurant was co-operating with council and health authorities.

‘‘The welfare and enjoyment of our guests is of utmost importance to us and we are committed to resolving this as our highest priority,’’ the spokeswoman said.

Calombaris owns a 25 per cent stake in Made Establishment, which controls Hellenic Republic in Kew and Brunswick, along with The Press Club and Gazi in the CBD.

The company experienced more misfortune last December, when thieves stole $20,000from its former South Yarra restaurant Mama Baba.

The thieves have not been apprehended, despite a tweet at the time from Calombaris that warned: ‘‘I will get u. Trust me. I will.’’