その行為は、会社の規則だけでなく、法律でも違法です。
Sono koui wa, kaisha no kisoku dakedenaku, houritsu demo ihou desu.
That act is illegal not only according to company rules but also by law.
違法な取引に関わらないよう、細心の注意が必要です。
Ihouna torihiki ni kakawaranai you, saishin no chuui ga hitsuyou desu.
The utmost care is necessary to avoid being involved in illegal transactions.