Thane sessions Judge V V Virkar convicted the sweeper after he was tried under various sections of IPC and also POCSO Act 2012.
He was also slapped with a fine of Rs 6,000.
In her submission, prosecutor Ruma Navale told the court that the accused who worked as a sweeper in a housing complex resided at Shivaji Nagar in Turbhe with his three children (two girls and a boy) and his aged mother.
The accused was a widower and an alcoholic, the court was told.
When the sexual abuse was repeated several times in mid-2013, the girl broke her silence before a neighbour who got the two sisters admitted at an orphanage with the help of an NGO but not before filing a complaint with Turbe Police.
The accused was charged under sections 323,376 and 377 of IPC and also sections 4,6,8 of POCSO Act.
