For some it would be the ultimate office farewell gift.

A worker at a Queensland employment agency allegedly took a tray of marijuana-laced muffins to a farewell party for a colleague, who had accepted a redundancy, last week.

The 42-year-old woman, who had also taken a voluntary redundancy, allegedly took the home-baked treats to the office morning tea held for her colleague last Wednesday at the Noosa branch of Employment Services Queensland.

Within hours of the morning tea for the company's departing site manager, the woman's co-workers started falling ill.

One woman, who collapsed and fell unconscious, was taken by ambulance to hospital.