Peter Galbraith, from the US, had angered Afghan President Hamid Karzai by criticising the country´s election commission.
Galbraith was said to have called for a complete recount.
Last week the top UN Afghan envoy, Kai Eide, Galbraith had left the country after a row between them, but he denied he had ordered him to go.
Afghan official: IS kills 17 Afghan Army soldiers in east