Brisbane's conference and exhibition centre, which hosted the G20 summit of world leaders last year, has been linked to a second salmonella outbreak.

The Brisbane Convention and Exhibition Centre has been linked to a second outbreak of salmonella poisoning.

It's been revealed about 10 people fell ill at a fundraising conference at the centre - a week before 250 people got food poisoning at a school principals' conference late last month.

At least 10 people fell ill after attending the earlier Fundraising Institute of Australia conference, with five confirmed to have had salmonella.

"We've been dealing directly with the exhibition centre who have now asked us to put these folk in contact with Queensland Health who are tackling the problem," Fundraising Institute of Australia chief executive Rob Edwards told the ABC on Friday.

A spokeswoman for the exhibition centre, which last year hosted the world's top leaders for the G20 summit, said it wasn't told of any earlier salmonella cases until after the principals' conference was over.

Queensland Health is still working to determine the source of the cases and has sent out a questionnaire in a bid to pinpoint the dodgy dish.