KANU leaders have said their candidate in the Kericho by election Paul Sang won with over 100,000 votes.
Party leaders, led by Chairman, Baringo Senator Gideon Moi said final results that showed JAP candidate Aaron Cheruiyot had won, was doctored.
According to the party, Sang garnered 126,193 votes against Cheruiyot's, 38,162 but was denied victory after the ruling jubilee coalition conspired with the Independent Electoral and Boundaries Commission (IEBC) to manipulate the voter transmission system.
The party provided statistics it claimed were proof of the election fraud, which employed a geometric progression formula that multiplied every vote cast for the JAP candidate by a ratio of 1.5.
"The formula was used by JAP to generate data through a computer programme so that at any given time during the tallying exercise, the JAP candidate's votes were constantly double those of the KANU candidate...The formula was to give the JAP candidate advantage," the party said in a statement read by the Party Secretary General, Nick Salat.
"... We as KANU and our campaign team declare that the Kericho by-election was rigged and IEBC was totally compromised and complacent to save face for some senior politician in the region," said Salat.
Senator Moi termed the elections a 'farce' and was not a true reflection of the people's will. He said KANU would organise rallies to 'thank' the people of Kericho for supporting the party and said it will field candidates in future elections.
"What happened was a total farce and a mockery of the democratic process. The IEBC was completely compromised and what emerged were not the true wishes of the people of Kericho," said Senator Moi.
"I want to tell the people of Kericho that we have a programme coming up in the next ten days where we will hold rallies to thank the people and to tell them that despite what happened, we are still with them.
"We are now emboldened and we are going to prepare ourselves for the 2017 elections. KANU will field candidates in the Rift Valley and in every single sector," said the KANU chairman.
During the by-election, IEBC announced Cheruiyot as the winner with 109,358 votes against Sang's 56,397.
KANU statement is the latest indication that dust from the by-election is yet to settle and that the party is keen to use the momentum generated in Kericho to cut down the influence of the Deputy President in the region.
KANU leaders claim the results announced were coming from a command centre away from Kericho and that forms given to agents at polling stations had been pre-filled.
It however said it will not contest the by-election in court as it has no faith in the country's judicial system.
"...Kericho has two senators- one a numeric system generated senator in the name of Aaron Cheruiyot, and the people's senator, Paul Sang," the party declared.
"IEBC was very hostile to us right form the day we were having our last rally...We are going back to the people to tell them that these people stole your votes but not your hearts," said Sang.