English to French Law/Patents Law (general)

this is the report of the public protector concerning the alleged improper refusal of a pupil at a high school.

The sentence reads as follows:
The Public protector conducted an investigation concerning the alleged improper refusal by the X high school to admit a learner to grade 8 in 2010.

I have translated the sentence as follows: "Le Protecteur du Citoyen a mené une enquête concernant l'allégation selon laquelle l'école secondaire de Milnerton aurait à tort, refusé la demande d'admission d'un élève de 8e année pour l'année 2010"

but it seems very convoluted and clumsy to me. And the translations I see in Linguee also do not seem appropriate.
your suggestions would be most welcome!