Mining sand -- mainly for concrete used in construction -- has boomed in Vietnam in recent years, prompting dire warnings over the environmental impact of overexploitation.

Police have recommended Nguyen Thanh Binh, the former chairman of the people's committee in An Giang province in the Mekong river delta, be charged with power abuse, according to Public Security News, the official mouthpiece of the Ministry of Public Security. The area is a hotspot for sand mining.

Binh, 59, and other officials ordered subordinates to issue a sand mining licence to the Trung Hau 68 company "in return for material gains", even though it did not qualify, state-controlled news site VNExpress said, citing police.

Between December 2021 and July 2023, the company mined over five million cubic metres of sand, supplying over a million cubic metres to a local road project and selling the rest for around $11.5 million, according to Public Security News.

In a 2023 report from conservation group WWF, experts warned that sand mining to feed Vietnam's construction boom was depleting resources so fast that the Mekong Delta -- the country's "rice bowl" -- could run out in just over a decade.

With less sand, river flows become lighter and faster, and hit the banks at greater speed, accelerating erosion.

Around 20,000 households need to be resettled because of the risks, according to Vietnam's natural disaster prevention and control department.

The WWF puts the figure much higher, saying half a million people could lose their homes.

Binh has already paid back $300,000 to the court, according to Public Security News.

The police recommended a total of 44 defendants face prosecution in the investigation.