His lawyer Ndegwa Njiru said the legislator was arrested at around 3 pm and booked at Kibii Police Station at 3:53 pm.
Mukunji was later picked up by officers from the Directorate of Criminal Investigations (DCI) based at Juja Police Station.
Njiru said the MP was booked under Occurrence Book (OB) number 06/07/07/2025.
The MP was held briefly for the “exclusive purpose of holding him” before being transferred elsewhere.
The police boss also indicated that Mukunji is likely to face charges of incitement to violence, without giving further details, he added.
The MP’s current whereabouts remain unknown, and his vehicle remains parked at Kibii Police Station.
His wife was also looking for him.
The National Police Service in a statement on Monday evening confirmed that Mukunji had indeed been arrested.
"A number of suspects have been arrested, including Gitonga Mukunji, MP for Manyatta Constituency," the statement read.
Chaos were witnessed in parts of Embu, which prompted police to use force to contain.
The Kenya National Commission on Human Rights said at least 10 people had died during the protests which rocked several parts of the country.
The commission in a statement on Monday evening, said there were 29 injuries, two cases of abduction and 37 arrests.
The shooting incidents happened in Ngong, Thika, Juja, Embu, Kangemi in Nairobi and Dagoretti among others.
The Commission said it noted that significant police barricades were erected on major roads and entry points, severely disrupting the movement of people, particularly in Nairobi.
“Additional blockades were reported in Kiambu, Meru, Kisii, Nyeri, Nakuru and Embu.”
"Many citizens were unable to report to work, despite the directive issued yesterday by the Cabinet Secretary for Public Service, Geoffrey Ruku, requiring all government employees to report to work without fail,” the commission said.
Numerous businesses nationwide remained closed due to fears of looting and destruction, it added in a statement.
Looting incidents were reported in six counties, and the Kerugoya Central CDF office was set ablaze by suspected criminal elements.
Further, learning was paralysed across the country as most schools and educational institutions remained closed.
