Statutory authority implies that an act is done by a person to fulfill his duty imposed by the state. Statutory authority is a valid defence under the law of torts. Vaughan Vs. Taffy Vale Railway Co. (1860) 5H&N 679, In this case defendant was authorized vide statute to run railway. Sparks from one of the engines escaped and set fire the woods collected by the plaintiff on the adjoining land.

It was held that as the defendant was under the statutory authority and was not negligent towards his duties he could not be held liable for the wrong ensued. Defence of statutory authority can not be pleaded, in case the act authorized by the statute are done without taking due care and caution in utter violation of condition imposed or in rash and negligent manner. No defence can override the basic legal rights and duties.