The arrest was made following a complaint made by the girl to the police.
A medical examination has confirmed that the girl has been sexually abused for nearly 10 years.
The suspect and girl are neighbours. The girl has been staying at the suspect's house when the parents went away and she has been sexually abused on such occasions.
The girl has complained to the police that the suspect continues to harass her and sought police protection to stop such harrsements.
Officers in Athurugiriya police station are conducting further probe.
(Source - Divaina)