The Orange Democratic Movement now claims Mathare MP Anthony Oluoch is being held at Kiambu police station.
This comes after he was arrested on Thursday, according to security officials who spoke to the Star.
"Mathare MP Antony Oluoch is being held at the Kiambu police station," ODM director of communications Philip Etale said.
Oluoch was fuelling his car at a petrol station near Nakumatt Junction on Ngong Road when he was arrested.
The MP is reported to have been whisked away by a vehicle bearing Tanzanian number plates.
"He whisked away in a vehicle with TZ plates while refuelling... Several Subaru cars were spotted around the scene," Etale tweeted on Thursday.
Oluoch becomes the second Azimio MP to be arrested amidst protests called by Opposition leader Raila Odinga.
Embakasi East MP Babu Owino was arrested at the Jomo Kenyatta International Airport on Tuesday evening, soon after arriving from a trip in Mombasa.
He was taken to Wang'uru police station where he was held and later returned to Nairobi on Thursday and presented at the Milimani law courts.
The Embakasi East MP was charged with conspiring to cause chaos.
Babu was detained overnight.
Several city Members of the County Assembly and activists were also arrested.
Earlier, Opposition MPs had decried the withdrawal of their security by the state over the planned three-day protests that will be coming to a close on Friday.
