Police in Kitui on Monday arrested the County Executive for Environment John Makau over the torching of a truck ferrying charcoal last week.
Mr Makau was summoned to the Directorate of Criminal Investigation offices in Kitui on Monday afternoon alongside county community liaison officer David Mbisi.
They were questioned by detectives over the incident.
The two senior county officers were put in custody later in the evening, awaiting arraignment in court.
County DCI boss Prosper Bosire confirmed the arrests, saying his detectives were looking for more suspects in connection with the incident.