Tamil Nadu Police have begun preparing “family tree” charts of people involved in ganja and other narcotics cases, as part of a wider monitoring and enforcement drive.

According to police, a statewide crackdown over the last three days led to the arrest of 621 people. Alongside raids, officers are compiling detailed profiles to track links around repeat offenders.

Police said those involved in drug offences often purchase assets in the names of family members or close friends. Such properties and related bank accounts are being identified and frozen.

For this, details of spouses, children, parents and other close associates are collected and mapped as a “family tree”. The list includes PAN, Aadhaar and bank account information.

In a recent case from Chennai’s Sengundram area, 21 kg of ganja was seized. Four people, including a YouTuber named Karthik and a woman named Devi, were arrested under the Goondas Act, police said.