"Legal action will be taken ... these are very serious actions," CAR Justice Minister Aristide Sokambi told the AFP news agency on Wednesday.
While he insisted the allegations concerned individual soldiers and not France or its Sangaris operation, Sokambi "deplore[d] the fact that we have not been associated with these investigations even though we a cooperation agreement with France".
Judges in France will investigate claims that French soldiers raped children in the Central African Republic, the state prosecutor announced Thursday.
French judicial sources say that 14 soldiers are suspected but that "very few" have been identified.
The French military opened an inquiry in July 2014 following the leaking of a UN dossier on the question, although the allegations were only made public last month when the London-based Guardian reported the story.
CAR Chief Public Prosecutor Ghislain Grésenguet then said he would ask the UN and the French authorities to pass on the relevant documents.
"An internal inquiry was carried out without our knowledge, although the victims were in Bangui," he commented. "NGOs and the UN came without informing us, we don't understand why."
A judge on Tuesday ordered the UN to lift the suspension of Anders Kompass, the aid worker who leaked the report, although the investigation into charges of breach of confidentiality continues.