Journalist Isaac Ongiri has won a petition challenging results for the Kasipul constituency ODM ticket.
The ticket was won by businessman Charles Ong'ondo who garnered 11,800 votes. The results were announced by returning officer Shadrack Kiplimo on Wednesday.
But Ongiri claimed he won the seat with 10,308 votes against Ong'ondo's 8,105 votes.
"Having examined evidence tabled by the aspirant before us, it is clear that no proper nominations took place in Kasipult," ODM appeals tribunal said on Saturday.
"Party regulations were not followed during the nominations and many irregularities have been proven by the petitioner whose name was also maliciously printed with missing details," the tribunal added.
The tribunal directed the party elections board to withdraw Ong'ondo's provisional certificate and carry out the process afresh.
Ongiri, however, wants the party to award him the certificate and requested the tribunal to investigate Ong'ondo's relationship with the returning officer, alleging the officer is the aspirant's in-law.
"I am happy that the ruling has given a clear picture of what happened on the ground. If the party fails to issue me with the certificate then I will move to the Political Parties Tribunal to demand it," Ongiri said.
He added: "Any attempt to award [Ong'ondo] victory over me is an act of fraud."
During the tribunal, a video was shows showing Ong'ondo dishing out money to presiding officers and clerks at Karabok Primary School.
But Ong'ondo, who is seen in the clip carrying about Sh1 million, told the tribunal the money was meant for transport for teachers who visited him at Karabok.
Ongiri argued that the act amounted to bribery, which can lead to his disqualification according to party rules.