The incident happened last night when Sonu Yadav, his 12-year-old niece Priyanka and his nine-year-old nephew Vikas were returning to Malhada village from Kohard village, police said.
The three were riding the motorcycle when it fell into the canal near Bawwa village after losing balance.
While Sonu and Priyanka were swept away by the currents, Vikas was taken out and saved with the help of villagers, police said.
Bodies of Sonu and Priyanka were fished out late in the night by the divers summoned by Nahar Chowki Police and the Kosli police.
While Sonu was a resident of Malhada village in Mahendergarh district, Priyanka hailed from Sihali village in the Mundawar area of Rajasthan.
Post-mortem was performed today in the Civil hospital at Rewari and the two bodies were handed over to their families, police said.