When I removed the ATmega328 , the current was only 9 mA (at 5V on 5V pin and 7 and 8.4V on Vin pin). Therefore I placed two other ATmega328's I have laying around. Both measure around 26 mA at the three voltages.
Clearly it is the ATmega328, but do you have any idea how come it differs from the others??