According to police, who registered FIR in the incident, the woman and her son hailed from Triplicane in the city.
The woman killed her husband and later sought the help of her son to dispose off the body in the morning, police said, adding, they packed the severed limbs and head in a bag before trying to dispose them off at the far-off Manali.
They had packed other parts in two more bags, police said.
With locals at Manali growing suspicious about their activity, they informed police, who found the duo giving contradictory replies before admitting to the crime. Police said they also found half-burnt body parts from the vicinity.
While a family dispute was suspected to be the reason behind the incident, a probe was on to ascertain the reason, police said.