Acting on a tip-off, police raided the house of Selvarani and seized the ganja along with Rs 12.66 lakh cash, Additional Superintendent of Police Velladurai said.
Selvarani's husband and two brothers were also in prison as they had been earlier arrested for allegedly selling ganja. One of the brothers had been detained under Goondas Act.
The entire family was allegedly involved in procuring Ganja from Theni district and selling it here, police said.