But the court said Thursday those violations were not sufficient to overturn the vote's outcome.
This means the final round of voting between the two leading candidates - ex-footballer George Weah and Vice-President Joseph Boakai - can go ahead.
The parties had to prove fraud was "not just at a few isolated centres but at most if not all polling centres", Banks said, and could not do so with the evidence presented. The National Elections Commission has been ordered to clean up its voter rolls before the second round can be held.
Some of the Supreme Court orders to the Electoral Commission include prohibition of the Chairman and NEC staff from speaking on any matter that may affect a party to the run- off and also fully comply with the electoral management laws of Liberia.
The second round of voting to succeed President Ellen Johnson Sirleaf had initially been set for 7 November.
Arguments into the appeal were held last week Friday December 1, after which the court reserved its opinion till today.
He said, the Supreme Court can not speculate that since it was proven that fraud and irregularities occurred at some polling places, it occurred Nationwide.
Hundreds of Liberians as early 8am this morning gathered on the grounds of the Temple of Justice, the seat of the Supreme Court to witness the final ruling from the highest court of the land.
Battered by back-to-back civil wars between 1989 and 2003 and an Ebola crisis that killed thousands from 2014 to 2016, Liberia's presidential election is considered a crucial test of the west African nation's stability and would be the first democratic transition of power in seven decades.