The Seventh Day Adventists church (SDA) has been barred from conducting services at the Homa Bay prison.
Its attempt to baptise 30 inmates on Saturday failed after the prison authorities turned away its leaders.
Prison boss R.J. Powon said he would not allow "strangers" onto the compound due to security concerns. He told the church to seek permission from the commissioner, Mr Abraham Kamakil.
Only Catholics, Anglicans, Protestants and Muslims are allowed to conduct services at prisons countrywide. Ironically, SDA is a Protestant church.
"The law is very clear because this is a protected area. Even warders are no supposed to discuss spiritual matters with the inmates unless with the express permission of the commissioner, Mr Powon said.
Meanwhile, the church yesterday appealed to Mr Kamakil for access to its followers.