Felipe Caceres was appointed deputy minister for social defence by President Evo Morales – who was once a coca grower himself.
Mr Caceres is a former mayor of a town in the coca-growing region of Chapare, and owns a small coca farm there.
Coca is used to make cocaine, but also has widespread ceremonial and medical uses in Bolivia.
Mr Caceres told the BBC he opposes US-backed efforts to eradicate crops across the country. He said coca was an integral part of Bolivia’s indigenous culture and was the only means of survival for many people. Many people in rural areas use the leaves in tea, or chew them to ward off hunger and altitude sickness.
Mr Caceres said he was convinced he would help lead a successful fight within President Morales’ government to end drug-trafficking in Bolivia. “What we say is no to drugs, but yes to the coca leaf,” he said, adding he would not stop production on his own plantation.
President Morales, who was elected last month as the nation’s first indigenous leader, wants to increase the production of coca for use in medicines, toothpaste and soft drinks.
He has promised to fight corruption, introduce a new tax on the wealthy, and renationalise energy companies.