The Brazilian Institute of Intellectual Property will officially announce its decision on Feb 13, the source said.
Apple could then challenge the ruling in the Brazilian courts.
A spokesperson with Apple in Brazil declined to comment.
With a swelling middle class anxious to go online, Brazil is one of the fastest-growing markets for smartphones in the world.
IGB Eletronica SA, a company formed after the restructuring of Gradiente, launched its "iphone" line of smartphones last December.