A person claiming land in equity may not bring suit to recover the same except within the period during which, by virtue of Section 15-1-7, he might have made an entry or brought an action to recover the same, if he had been entitled at law to such an estate, interest, or right in or to the same as he shall claim therein in equity. However, in every case of a concealed fraud, the right of any person to bring suit in equity for the recovery of land, of which he or any person through whom he claims may have been deprived by such fraud, shall be deemed to have first accrued at and not before the time at which the fraud shall, or, with reasonable diligence might, have been first known or discovered.