The Romanian electoral commission did that. I'm sure they had their reasons - the article cites "statements contradictory to democratic values" (last November) and Russian interference. I guess they have something to back that up with. The Guardian does not say, but until someone convinces me otherwise (edit: that will be really hard after me reading this) I will give the electoral commission the benefit here.

This is government at work. If they really wanted to suppress democratic voices they'd not go about it in a way that just gives free publicity to her and better chances to the remaining far-right candidate.