Smart Adeyemi of the All Progressives Congress (APC) Wednesday took his oath of office to represent Kogi West in the Senate.
The swearing-in was done by the Clerk of the Senate, Nelson Ayewoh, at the start of plenary.
His swearing-in comes three days after he was pronounced winner of the Kogi West senatorial district rerun election.
He will replace the Dino Melaye of the Peoples Democratic Party (PDP) who lost his bid to retain his seat in the Senate.
Mr Adeyemi is returning to the Senate about five years after he lost the seat to Mr Melaye at the 2015 election.
At the end of the senatorial election on Saturday, Mr Adeyemi polled 88,373 votes while Mr Melaye recorded 62,133 votes, according to the results announced by the returning officer, Olajide Lawal.
The Independent National Electoral Commission (INEC) had over a week ago declared the election inconclusive because the margin between Mr Adeyemi and Mr Melaye is lower than the number of “registered voters in 53 polling units of the 20 registration areas in the zone where elections were cancelled.”
After the main election on November 16, Mr Adeyemi polled 80,118 votes while Mr Melaye polled 59,548 votes in the election characterised by violence, ballot box snatching and vote buying.
The margin of 20,570 votes between the two candidates was far less than the 43,127 registered voters in the 53 polling units where elections were cancelled; hence, the rerun.
Mr Melaye has vowed to challenge the result of the election in court.