No ones knows for sure, but people suspect that he stole something from the company.
この場合、次のような言い方ができますよ。
ーNo ones knows for sure, but people suspect that he stole something from the company.
「誰も確かなことは分からないけど、彼は会社から何かを盗んだと疑われているみたい」
No ones knows for sure「誰も確かなことは分からない」
to suspect「疑う」
to steal something from ...「…から盗む」
ご参考まで!
It seems like he was suspected of stealing from the company.
I heard he was under suspicion for stealing company property.
It seems like he was suspected of stealing from the company.
I heard he was under suspicion for stealing company property.
・Suspect of...
「〜の疑いをかける」という表現です。受け身の be suspected of stealing にすることで「盗んだと疑われていた」となります。
・It seems like...
「〜のようだ」「〜みたいだね」というニュアンスを文全体に加えます。