Shannu Khatun, who begs to make a living, said she gave away her 16-month-old son a few days ago near Forbesganj railway station so that he could be better looked after, but denied having received payment, SP (Araria) S Lande said.
At the same time, her 8-year-old daughter said her younger brother was sold for Nepalese Rs 100 (INR 62) and not given away, he said.
Khatun, a resident of Madanpur village, said she took the step in desperation as she was finding it difficult to support her physically challenged husband, daughter and the twins, he said.
Efforts are on to trace the child, Lande added.