Police looking for a woman and her seven-year-old son, who are believed to have been lured into a religious cult, hope to trace them by mobile phone.
They have sought help from phone company Safaricom to pinpoint the hideout.
The head of the Special Crime Prevention Unit, Mr Nyagah Reche, said yesterday he had stepped up the search because he believed the woman and the boy were in Kenya.
The woman, he said, had been in contact with her parents and police on her cellphone, but she was reluctant to disclose her hideout.
The investigators visited Safaricom offices yesterday and sought help to track down the signal which would give a hint over her whereabouts.
"Safaricom technicians have been of much help and, though we have not traced the hideout, we are optimistic we will find them," Mr Reche said.
Mr Roland Gianstefani, 42, a member of an international religious cult, is being held at Gigiri police station, Nairobi, by officers investigating the disappearance of the 27-year-old woman and the boy.
He was picked up from the city streets on Friday as he gave out religious literature to passers-by.
Mr Reche said he wanted to talk to Mr Gianstefani's wife, Susan, who he said he believed would she light on the woman's whereabouts.
"Susan vanished after her husband was arrested, and efforts to trace her have not borne any fruit," he said.
Mr Gianstefani and his wife were in July 2000 given suspended six-month jail sentences by a British judge for refusing to reveal the whereabouts of a teenage boy, who had left home to join the Jesus Christian group.
Bobby Kelly, who was then 16, sparked a worldwide alert when he left his family to join the sect. He was found a month after his disappearance.
Mr Reche said the woman had been receiving calls on her cellphone from her parents and the investigators. However, she refused to disclose her whereabouts and that of her son.
"We believe Safaricom are going to help us track down the signal which can lead us to where they are," Mr Reche said. The cult, formed in Sydney, Australia, by Mr David McKay, has spread to Europe and Africa.
It has been described by British newspapers as a nomadic religious cult that calls on members to forsake their jobs, bosses, families and friends to show pure devotion to God.
Mother and son left their parents' home on the Kiambu road on June 10 to visit a Christian preaher for a week.
The parents sought police help after efforts to persuade their daughter to return hoome failed.
CID chief Joseph Kamau said that although his officers were not getting new leads, they would not give up until the woman and her son were found and the secrets of the cult exposed.
"We have almost hit a brick wall because Gianstefani has not given our investigations strong leads," he said.
After officials of the Australian high commission visited Mr Gianstefani in police cells, the second secretary and vice counsul, Ms Kristy Hughes, wrote to him saying the mission could only help to inform his family about his arrest, but could not meet his legal fees.
