The suspects will be held at Gigiri Police Station.
In his affidavit, Tegei claimed Githinji and Mwenda were placed at the scene of the murder . The two were arrested within Meru while Kathambi was arrested in Muthaiga, Nairobi County.
"Preliminary investigations indicate that the first and second respondents have been placed at the scene of the crime of murder at Mutonga River in Tharaka Nithi County," claimed Tegei.
Further, Tegei claimed that there could be more persons who were involved in the heinous crime, and who are still at large.
"Owing to the complexity and the nature of the case, the investigating officers will need time in order to carry out comprehensive and in-depth investigations with a view of retracing the last movements of the deceased person," he said.
According to Tegei, the blogger was lured through a phone call that he was allegedly to meet Meru Governor Kawira Mwangaza for a truce and plans to work together. The lead investigator claimed that the victim was a critic of the embattled governor.
He stated that Muthiani left his home in Igembe South to Meru town where he met the trio and thereafter went missing.
His wife had reported at Maua Police Station that she had tried to contact him but in vain.
The officer said local residents stumbled on a body on December 6, 2023, at Mutonga River and alerted authorities in the area.
The body was retrieved the following day and taken to Marimanti Level Four Hospital.
The court heard that his family identified the body on December 18, 2023.
Tegei said the police will comb through the trio's phones as they try to pin their participation and also record statements to determine whether to prefer charges or not.