A brother to fugitive murder suspect Kevin Kinyanjui Kang'ethe was detained Monday for questioning over his escape from police custody.
Also being questioned is the brother’s girlfriend, police said.
They are persons of interest in the case where Kangethe is wanted for murder in the USA after escaping from lawful custody.
The two were picked up on Monday evening and taken for grilling.
It is not clear what police want to learn from them but insiders said the brother may have talked to Kangethe after he escaped from Muthaiga police station on February 7.
Police believe Kangethe met his brother after he escaped custody.
This happened somewhere in Kiambu before they parted ways.
Dozens of detectives have been tasked to hunt Kangethe for possible arraignment and extradition to the US.
His cousin and lawyer Beatrice Ng'ethe was also last Friday arrested and detained for questioning over the saga.
She was detained in police custody before being released on Sh100,000 police cash bail.
This is in relation to the ongoing investigations to the escape which police say has put them in shame.
Director of DCI Mohamed Amin said Beatrice was interrogated and released in connection with the escape of Kangethe.
“She was released as we investigate the matter,” he said.
DCI sleuths picked her up from her house in Kiambu on Friday morning as she prepared breakfast.
Beatrice who is Kang'ethe's cousin, became a person of interest after phone records revealed that she was in communication with the fugitive days before he strolled out of Muthaiga Police Station without a trace.
Police said a day before the murder suspect vanished, the lawyer was at Muthaiga police station to see him. But she has denied any role in the escape.
The suspect is believed to be hiding in and around Nairobi.
Detectives say he is using mobile phone numbers registered by relatives.
A warrant of arrest was last Friday issued against Kang'ethe.
Milimani Chief Magistrate Lucas Onyina gave the orders after an application by the prosecution, who said Kang'ethe is a dangerous person and on the run.
"In the view of the application that the respondent escaped jail, a warrant of arrest is issued as sought," Onyina ordered.
The court heard that Kang'ethe escaped lawful custody on February 7, at around 4 pm.
Four police officers who were on duty when Kang'ethe escaped from custody have been interdicted.
The suspect was awaiting extradition on a Massachusetts warrant alleging he killed his girlfriend and left her body in a car at the Boston airport.
On Wednesday, he escaped from custody as he met a lawyer.
He was to appear in court on Friday, February 9 for directions on his extradition case.
Witnesses said he was barefooted when he ran out of the station and took a matatu headed for Thika.
Nairobi police boss Adamson Bungei said as part of disciplinary measures within the police force, two additional senior officers overseeing the four policemen in question have been reassigned to different duty stations.
“The four will face other charges in court including aiding the escape of the wanted suspect,” he said.
“We are investigating further to establish if there other players in the issue.”
Kang'ethe's lawyer, John Ndegwa Maina was also arrested over the escape.
Maina was detained at Muthaiga Police Station shortly after Kang'ethe's escape at around 5.30 pm on Wednesday, February 7.
Maina had visited Kang'ethe, in his capacity as his advocate, four times before his escape.
Kang’ethe is accused of killing a 31-year-old Kenyan-born Margaret Mbitu who was based in Whitman, Massachusetts whose body was discovered inside a vehicle at Boston's Logan Airport in November last year.
He was arrested in Westlands on January 30 and was to be extradited when he escaped from custody.