The unemployed accused, living in Verna village near here, molested his 13-year-old daughter five days back, they said.
While she was being counselled by a local NGO yesterday, it also came to light that the accused had allegedly raped his elder daughter in 2008 when she was around 13-year-old.
Verna police arrested the accused yesterday and booked him under relevant sections of Goa Childrens' Act.
The mother of the two girls has been working abroad, police added.