The Aavin milk scam involved continuous diversion of supply vans from various districts midway on the route to Chennai and diluting with water. Aavin is the co-operative milk society of the state government of Tamil Nadu, a South Indian state. The scam was found out on 19 August 2014 when police investigated the van from Narayanapuram village that was carrying empty milk cans. Tiruvannamalai chilling centre bound to Chennai. Following the news, the state minister for milk was stripped of his post, nine Aavin officials were suspended and the chief suspect, Vaidyanathan, was arrested. The initial estimate of the losses have been valued at one per cent of the total ten lakh litres, amounting to ₹23 lakhs a day.
The Dairy Development Department was established in Tamil Nadu in 1958 and the administrative and statutory control of all the milk co-operative societies in the state came under its jurisdiction. The Co-operative Milk Producers' Federation Limited was registered on 1 February 1981 and the commercial activities like procurement, processing, chilling, packing and sale of milk were transferred from the department to the Federation, which was called Aavin. The dairy units in the state operate in a three-tier model at state, district and village levels. Aavin was one of the few original agencies using vendor machines in India. Booths were run in the capital city where flavoured milk, milk sweets, ghee, butter and plain milk are sold. Each year, the organization introduced new products. The agency provided high-quality milk at reasonably low cost in the state.
Several policy changes were made in Aavin administration in 2008, like procuring milk with less SNF (solid non-fat) content from 8.6 to 7.9 SNF, and this helped suppliers to adulterate milk. During the same period, the transport department of Aavin which controls the milk tanker operation was reduced to a clerical department, outsourcing operations related to milk tankers and drivers. This helped Vaidyanathan to strengthen his coterie and also control the outsourced milk tankers.”
Aavin procures milk from various district milk unions in the state through delivery tankers. Vaidyanathan, the person involved in leasing the milk trucks, is believed to have diverted the trucks to Govindapuram, a village in the outskirts of Tindivanam. The Vellimedupettai police on complaints from local residents on 19 August 2014 raided the vehicles and found that milk vans carrying supplies to Aavin in Chennai were diverted midway and adulterated with water. The police arrested eight people involved, but found that they were involved in the business for the past six months. Initial investigations revealed that the modus operandi was diversion of hundreds of milk tankers (each having 12,000 litres of milk) near a preset post in Tindivanam, where 2,000 litres of milk were taken off from the sealed containers and refilled with water. All the tankers were owned by AIADMK party person N. Vaidyanathan. The stolen milk was siphoned off to private milk agencies, which sold or produced dairy products. The investigation also revealed that the operation was carried out for more than ten years. The kingpin of the operation, Vaidyanathan, started as a concessionaire of Aavin milk in 1987 and subsequently emerged as an owner of hundreds of trucks that supply milk to Aavin. He is alleged to have the backing of several officials who could change policies for his benefit. The initial estimate of the losses was one per cent of the total ten lakh litres, amounting to ₹ 23 lakhs a day. The investigating agencies then traced the owner of the truck to be Vaidyanathan and arrested him in Chennai.