Can I cite a certain source in another language even if there EXISTS an English translation of said source?

I'm not a native English speaker. I would like to cite a book originally written in German for a writing sample to be sent for admission purposes to a graduate school in the UK (MA programme).

There are at least two translations of said work: Romanian and English. I have read the Romanian translation, not the English one, because it was far more convenient to do so. Naturally I translated the Romanian passages to English and cited them appropriately, but the citations are based on the Romanian translation (e. g. I have cited a passage to be found on page 52 of the Romanian translation).

Is it a problem that instead of citing the English version of the book, I have cited and translated the Romanian version? I'm afraid so, because the reviewers probably don't speak Romanian, therefore they can't check whether the cited passage is REALLY there in the Romanian translation or I just made up the whole thing. Plus they might think I'm lazy.

If this is indeed a problem, I have to find all of these passages - which I have originally read in Romanian - in the English translation and rewrite all footnotes, bibliography etc. (e.g. the passage which is located on page 52 in the Romanian translation might be located in a different place, say page 63 in the English translation).

I have to know! Thank you!