Former Sports Cabinet Secretary Rashid Echesa, has been transferred to Directorate of Criminal Investigation (DCI) headquarters in Nairobi.
Echesa was arrested on Friday when he presented himself to police in Mumias after he had been declared armed and dangerous.
During the Matungu by-election, Echesa was captured on video assaulting an official of the Independent Electoral and Boundaries Commission (IEBC) in Matungu.
Mr Echesa, a close ally of Deputy President William Ruto, spent the night at the Kakamega police station before he was picked by a team of officers who drove with him to Nairobi early Saturday.
Western region police commander Peris Kimani confirmed that the ex-sports CS was transferred to DCI offices in Nairobi but declined to give further details.
“There are investigations being conducted by the DCI and that’s why he is being transferred there. This matter is being handled by the DCI,” said Mrs Kimani.
The by-election in Matungu was marred by violence and incidents of wide spread voter bribery.
Echesa is accused of slapping an IEBC official during an altercation which erupted over United Democratic Alliance (UDA) poll agents who had been ejected from the polling centre.
He later went into hiding after the video went viral social media.
On Thursday, police officers raided his home at Shibale in Mumias West constituency but did not find him.
His arrest came after police asked him to surrender to the nearest police station.
The IEBC chairman Wafula Chebukati had asked police to arrest Echesa and demanded his prosecution.
ODM Secretary General Edwin Sifuna had called on police to ensure all suspects who took part in acts of violence during the by election are prosecuted.
“We shall be setting a bad precedence if the perpetrators of violence acts in Matungu will go scot-free. Action has to be taken against them,” said Sifuna.
The body guard of Kakamega Senator Cleophas Malala was arrested after he shot at a group of youths, injuring a resident at Munami polling station.
The administration police constable was disarmed and arrested along with six other people who stormed the polling station and disrupted voting, claiming IEBC officials were watching as ODM agents were stuffing ballot boxes without stopping the malpractice.
The administration police constable and the six suspects will appear in court on Monday.