Police in Nyeri have arrested a 48-year-old man for allegedly defiling his seven-year-old step-daughter.

Detectives apprehended Moffat Mwangi Wangechi on Wednesday after the grade-one girl narrated her ordeal to the neighbours who later reported to the police.

According to a police statement posted by the Directorate of Criminal Investigations(DCI) the suspect was alone with the girl when the incident took place.

The family of three is said to be sharing a bedroom, police sources added.

The grade-one girl has since been treated and the police are gathering more forensic evidence to charge the culprit with defilement.