Chennai: A four-member gang smuggling ganja into the city from Andhra Pradesh posing as a family was arrested on Saturday. Police tracked them down using a nickname and the last three digits of a phone number, after an initial seizure of 21kg of ganja near Thiruvanmiyur bus terminus.Police said the Adyar Prohibition Enforcement Wing (PEW) received a tip about sale of ganja in bulk across East Coast Road (ECR) neighbourhoods.After mounting surveillance, police nabbed a suspect named Adithyan alias Harish, 23, of Puducherry with 21kg of ganja. During questioning, Adithyan refused to reveal his source but mentioned a man named ‘Sithaappu’ and a mobile number ending in ‘532′.Using advanced tower dump and network tracking technology, police located the suspect’s mobile activity to Madhavaram and traced the movements of the phone towards Visakhapatnam. Officers identified and intercepted a long-distance bus suspected to be carrying the supplier. They apprehended Murugesan, also known as Sithaappu, a habitual offender from Telangana with more than five ganja cases pending against him. He was found carrying 4 kg of ganja at the time of the arrest.During inquiries, the bus conductor told police that two women accompanying Murugesan had boarded a different bus. Acting swiftly, police tracked and arrested Baby, 36, and Pooja, 20, both natives of Telangana. Investigation revealed the women were posing as family members to avoid suspicion while smuggling large quantities of ganja from Andhra Pradesh and Odisha to Chennai by train.To evade security checks at Chennai Central, the women handed over the narcotics to accomplices at intermediate stations such as Perambur while the train slowed down, said police. They were produced in court and remanded in judicial custody.