The police said the boy has been identified as a class 12 student of a school in Namakkal, who had appeared for his board exams and was waiting for results.
In the note, the 17-year-old wrote that his father should not be allowed to perform his last rites. He even tasked another family member with it, the police said.
There was a promise of prohibition in Tamil Nadu when the AIADMK, led by Chief Minister J Jayalalithaa, came to power in 2015. But despite support from most political parties, the matter has not been pursued.
Tamil Nadu was the first state to have a total ban on alcohol. In 1971, the DMK government led by M Karunanidhi had lifted it despite stiff opposition.
The Tamil Nadu government earns around 27000 crore through liquor sale in government owned outlets.
After her death in December 2016, the government led by E Palaliniswami had shut 500 liquor shops in February last year as part of the plan, but no further measures were taken.
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