Twelve Chinese nationals were arrested in South C estate, Nairobi County, on Wednesday for allegedly engaging in prostitution.
In a statement, Director of Immigration Services Alexander Muteshi said they arrested eight girls and four men.
Mr Muteshi said the arrests followed a tip-off and independent investigations.
Officers from the Directorate of Criminal Investigations and immigration officials raided the house at 5am in an operation that targeted violators of immigration laws, fugitives and human traffickers.
"It is suspected that the two houses have been operating as brothels," he said.
Mr Muteshi said police records show that one of the men arrested was put in a watch list in May last year, on suspicion that he was involved in prostitution and illegal gambling.
He was deported and banned from returning to Kenya but did so using a different passport.
The statement said the 12 were prohibited immigrants, who defied immigration laws and the requirements for working or doing business in Kenya.
They were taken to Jomo Kenyatta International Airport for processing and subsequent deportation.
The arrest came months after Interior Cabinet Secretary Fred Matiang'i declared war on illegal immigrants.
Two weeks ago, Kenyan police raided the African headquarters of the China Global Television Network in Nairobi and briefly detained several journalists.
The Chinese embassy in Nairobi has complained about police swoops that have seen its nationals with legal documents hauled into police stations for verification.