Nine years after imposing a statewide alcohol ban to curb addiction, domestic violence, and financial ruin among its poorest families, Bihar - India's poorest state - still struggles to gauge the policy's effectiveness.

The gaps in implementation became glaring as the BBC shadowed Bihar officials in a misty October morning raid on bootleggers.

Armed excise officers, with a sniffer dog, sped across the Ganges on a boat to raid an illegal distillery.

On reaching the outskirts of the capital, Patna, the team found a ramshackle setup of a dozen metal drums - part of a makeshift apparatus fermenting jaggery, a type of cane sugar, into country liquor.

Vapour rose from the drums embedded in the riverside mud, the surfaces still warm.