Police warning: incorrect wheel size on Audi A8L D2

[iGO]

Hi everyone
Today I was stopped by police and officer gave me warning for incorrect size wheels.
He told me that wheels are not manufacturer/AUDI ones, not designed for this vehicle and doesn't fit arch correctly
Maybe someone know regulations and what does it mean CORRECT wheels?
How much I know tire tread should stay under arch.

Thanks for any help
Igor