Fraud is not void,

-    Order made by a Court, tribunal or other authority acting without jurisdiction as regards subject-matter, pecuniary value or territorial limits – Void – Order obtained by fraud, however, not void but only voidable.

An order obtained by fraud is not void, but only voidable. It remains operative as long as it is not set aside, rescinded, or recalled, by a competent authority in proper proceedings.

While it is true, as has been so often stated, that fraud vitiates all proceedings, it must nevertheless, be borne in mind that allegations of fraud generally raise mixed questions of law and fact which can only be established in an elaborate inquiry. It is for this reason that an order obtained by fraud can be regarded as only being voidable at the instance of any party adversely affected by it.

The  Chief Settlement Commissioner, Lahore
Versus
Raja Mohammad Fazil Khan and others
PLD 1975 Supreme Court 331