Shortly before his death, the independent journalist Jagendra Singh wrote a social media post about the threats he believed he faced for investigating sand mining in northern India.

“Politicians, thugs, and police, all are after me. Writing the truth is weighing heavily on my life.”

Two weeks later, on 1 June 2015, the veteran reporter was set upon by a gang that entered his home, doused him with petrol and set him alight.

He later died of his injuries.

Singh had been investigating land grabs and alleged illegal extraction of sand from the Garra River. Sand is mined both legally and illegally, to extract minerals and for construction and reclamation projects.

The multibillion-dollar business, which supplies up to 50bn tonnes to the construction industry each year, is prohibited in an increasing number of states around the world as erosion, floods and other environmental consequences become harder to ignore.

Singh’s son said his father had previously been threatened. Police concluded he had killed himself. The family said they were given 3m rupees (£34,000) as a “wedding gift” for Singh’s daughter. They took it to mean that they should accept the police verdict.

Singh’s daughter, Diksha, has refused to touch the money. She said her father was fighting for justice. “My father was one such rare people who exposed the truth.”

Since Singh’s death, two other journalists have been killed while investigating sand mining in India. Karun Misra died in February 2016, and Sandeep Sharma was killed in March 2018.