Malaysia had issued sand export licences to India, but has yet to confirm if the sand recently shipped to the Tamil Nadu state was by a company with legal paperwork, Minister of Natural Resources and Environment Wan Junaidi Tuan Jaafar said yesterday.

"There seem to have been permits issued," he told The Straits Times.

The environment ministry is working to identify the Malaysian company that was reported by Indian news dailies to have exported a sand consignment of 55,000 tonnes last month.

"That can be identified very soon within the week, where the source of the sand is. If they have permission to send sand to India, then there's nothing wrong with it. It's just a business arrangement," said Datuk Seri Wan Junaidi.

Last Sunday, he told a Malaysian news website that no permits were issued to export sand. Mr Wan Junaidi said he learnt about the existence of issued permits on Monday.

A construction boom in India, followed by a shortage in river sand needed by developers had led to escalating sand prices and also reports of illegal sand mining in southern India.

The Times of India reported that Malaysian sand was selling for half the price of Indian sand, at about 60 rupees (S$1.26) per cubic ft, compared with river sand sourced in Tamil Nadu, which could be sold at between 110 and 120 rupees.

The daily reported in the middle of the year that Malaysian firms were in talks to export sand to two southern Indian states, Tamil Nadu and Karnataka.

A check by The Straits Times found that an Indian trading company in Tamil Nadu that deals with fresh produce was advertising sand sale on its Facebook page.

The company said the Malaysian river sand came from Sitiawan, a coastal town in Perak state.

Pegged as the first sand import in Tamil Nadu, the recent shipment is stuck at a port in Tuticorin, India, awaiting permission from the district authorities to transport the sand out of the premises.

Sand mining often attracts controversy with complaints of soil erosion, reduction in water quality and destruction of the river ecosystem.

Malaysia had banned sand exports between 1997 and 2015, but lifted the ban last year.