Health officials say an outbreak of the potentially fatal E.coli O157 infection could be linked to food sold at Glasgow's Hydro concert venue.
Seven people - one from Glasgow, two from Lanarkshire, three from Lothian and one from Cumbria - are recovering at home after being diagnosed.
Health officials say the cases may be linked to burgers sold at The Hydro.
Anyone who attended the venue between 17 and 25 January, and who feels unwell, is asked to contact their GP.
Symptoms to look out for include stomach cramps, diarrhoea (often bloody), nausea and fever.
The seven people who contracted the infection all attended Top Gear Live on 18 and 19 January.
NHS Greater Glasgow and Clyde said possible links to other food sold at The Hydro were also being investigated.
Dr Gillian Penrice, consultant in public health medicine at NHS Greater Glasgow and Clyde said: "Investigations are underway to identify if there is any common source.
"While there is no conclusive evidence our initial investigations have indicated that there may be a link to the consumption of burgers at the SSE Hydro and Glasgow City Council environmental health officers are working closely with the vendors to ensure all appropriate food hygiene standards are being met.
"I would ask anyone who has attended the Hydro recently and who has experienced or is continuing to experience symptoms including stomach cramps, diarrhoea (often bloody), nausea and fever to contact their GP."
A spokeswoman for The Hydro said: "We have been contacted by environmental health in relation to an investigation into an E.coli outbreak which they believe may have been connected to one of the catering outlets on our premises.
"We are awaiting further details to establish the exact cause of this isolated incident and our catering partners have been working closely with environmental health officers.
"The initial review of our caterers' standard procedures have been found to be satisfactory and environmental health officers have seen nothing in their processes and practices which concerns them.
"We wish to assure the public that at this time we have no significant concerns in relation to catering for our patrons."
Most E.coli strains are harmless, E coli O157, however, can cause serious illness.
The bacterium is spread in a number of ways, including eating or drinking contaminated food or drink, direct or indirect contact with infected animals and person-to-person contact.
If humans come into contact with it, the toxins produced can cause illness such as diarrhoea or abdominal cramps.
Some patients suffer from a complication, hemolytic uremic syndrome (HUS), which kills red blood cells and can cause kidney failure.
In some cases the illness can be fatal.
In the worst recorded outbreak, 21 people died in Scotland after attending a church lunch in Wishaw, Lanarkshire, in 1996.