Murdered Kitui teacher Daisy Mbaluka Mbathe's husband was among six more suspects arraigned on Monday in connection to the crime.
Lawrence Mbindi Ndolo and the others were, however, not required to plead to the charge as detectives sought to detain them for 21 days in order to finish the probe.
Mr Ndolo, who was arrested on Sunday after hours of questioning by homicide detectives, was presented before Kitui Chief Magistrate Stephen Mbungi and detained as a person of interest.
The other suspects include Mutiso Mulwa, the man who claimed to have been tortured in the teacher’s house on New Year's Eve, his mother Nzangi Mulwa and his wife Racheal Nzangi Mutiso.
The others are Mr Mulwa's maternal uncle Amos Jacob Kithikii and neighbour Martha Kisilu,
This brings to eight, the number of suspects arraigned so far following the crime on January 6.
Mr Wambua Mwangangi and Mr Chris Kyalo Muli were arraigned on January 9 over the killing of Mbathe, who taught at Ndooni Primary School.
In his application for the suspects' detention, lead investigator Bernard Jefwa said they should be held at separate police stations in order not to share information.
The magistrate granted the request by the Directorate of Criminal Investigations (DCI) despite objections by a lawyer representing the slain teacher’s husband.
Mr Mulwa and his uncle Mr Kithikii were dramatically arrested moments after granting Nation journalists an interview near their home at Makuka.
Detectives said they 'played hide and seek' with them for three days so they were surprised to find them within their village.
In a statement recorded on January 2, Mr Mulwa claimed the teacher lured him into her house and that he was tortured for hours by a gang on December 31.
He filed the report, reference number OB/17/02/2020 at Endau Police Station, four days before the teacher was ambushed by a gang that hacked her to death and then set her body on fire.
Detectives established that Mr Mulwa was among people at the scene of the murder and that he neither sought treatment for the alleged injuries nor followed up with police following the torture complaint.
The suspect was supposed to return the P3 form filled in by a medical expert to show the extent of the injuries. He had not done so by the time the teacher was killed.
Mutito Sub-county Police Commander Consaga Malasi said the teacher was killed by people who decided to take matters into their own hands, perhaps enraged by the claims of torture and extortion.
A detective familiar with the investigations, who did not want to be named, claimed Mr Ndolo's phone records revealed one of the suspects called him from the scene of the murder.
The husband, who works in Nairobi, claimed his marriage had been on the rocks and that he once had to seek police protection from the extortion gang following threats.
“I was threatened by the man who had been cohabiting with Daisy and I received many complaints from people including my friends, who were victims of the extortion ring," Mr Ndolo claimed.
"I reported the matter at Endau Police Station on September 14 last year."
Last week, Mr Ndolo recorded a statement with police over his wife’s killing, detailing his tribulations at the hands of a gang that he claimed forced him to stay away from his family.
“I believe my wife’s murder was planned by the man who cohabited with her to cover up the crimes they had committed together and to benefit from huge amounts of money extorted from more than 40 victims," he said.
In an interview with the Nation, he said he was saddened but not surprised by the turn of events because he was aware of the crimes that were being committed.