The woman, Rosemary Chukwu, claimed her pastor had sent her to kidnap the boy for ritual purpose.
According to Vanguard, Nwankwo, who was arrested around Ebute Metta area of Lagos yesterday, is currently at the State Criminal Investigation Department, Yaba, Lagos.
Nwankwo has since denied that the building on Oshodi Street in Ikorodu where eight victims were found is a ritualists' den. He said the building was used to keep lunatics.