That's interesting. Are u sure it's a fungus? I know they can suffer fungal problems but perhaps it's suncald. That happens if the leaves are exposed to too much direct sunlight. Does it look anything like this?
This site http://camelliasaustralia.com.au/cultivation/ongoing-care/pests-and-diseases/ said something pretty interesting:
"Camellias planted in full sun or against a north or westfacing wall often get sunscald. Leaves will develop scorched or bronzed/yellow areas on the side of the plant directly exposed to the sun. Leaf-spotting fungi may infect the damaged leaves. Sunscald is a particular problem on camellias transplanted from shaded to sunny locations."