His main challenger, Bina Tubi of the Jubilee Party, finished a distant second with 634 votes.
The by-election was called following the death of their father, Mohammed Tubi, setting the stage for a deeply personal and politically charged succession battle.
The race effectively became a two-horse contest after National Economic Democratic Party (NEDP) candidate Isaac Fayo withdrew in favour of Tubi Mohamed, consolidating support behind the UDA flag.
Speaking after casting his ballot at Algani polling station, Tubi Mohamed acknowledged the unusual nature of competing against his sister, saying politics often overrides family considerations.
“Unajua siasa haitambui ndugu ama dada. Kuna mambo mingi kwa siasa. Kama mimi wazee ndiyo waliniekelea mkono,” he said, suggesting elders had endorsed his candidature.
A few kilometres away, Bina voted at Kinna polling station but declined to address the media, leaving her agents to voice concerns over the conduct of the election.
Bina’s camp alleged irregularities, claiming the process was not free and fair.
“This election is a sham. We want to ask IEBC whether this is a free and fair election,” said one of her agents, who also alleged incidents of voter bribery at Kina Primary School.
However, officials from the Independent Electoral and Boundaries Commission dismissed the claims, maintaining that the exercise met required standards.
IEBC representatives overseeing the poll said they had not recorded any incidents of malpractice within polling areas, while security agencies reported that adequate measures were in place throughout voting and tallying.
Isiolo County Commissioner David Kiprop noted that security had been maintained from polling stations to the tallying centre to ensure a smooth exercise.
Despite the high-profile nature of the sibling rivalry, the by-election recorded an estimated turnout of about 30 per cent, highlighting concerns over voter apathy in the constituency.
