The incident took place at Munnawali village in the district.
The body of Harpreet Singh (14) was found on the bank of Dharmai Canal today, they said.
The boy had been missing since January 31, following which his mother Tajinder Kaur was questioned.
During interrogation, she confessed to have killed the boy, police said.
She said the son was a hurdle in her affair with her paramour Lakhwinder Singh, a resident of Paniar village under Dina Nagar police station here, police said.
Both the accused have been arrested, police said.
