Chennai, Oct 8 : Directorate of Enforcement (ED) on Sunday visited sand quarries across Tamil Nadu to measure the sand available at stock yards. The ED officials were assisted by engineers of the Tamil Nadu Water Resources Department to provide information regarding the volume of sand being mined. The premium investigation agency is probing allegations that large quantities of sand was excavated from river beds and sold illegally which has caused huge loss to the state exchequer as the illegal sale is bypassing the online mechanism for sale which was legally adopted. The ED is probing money laundering offence in sand mining business after it conducted raids on sand stock yards on September 12. The agency had then during the raid seized incriminating documents and fake receipts pointing at illegal sale of sand. Meanwhile, the Tamil Nadu state sand lorry owners association said that there was an acute shortage of river sand in the market as the volume of sand available through online mode has come down drastically. Tamil Nadu Sand Lorry Owners Federation President Sella Rajamani called upon the state government to open all the sand quarries and commence full-fledged sale of sand through online mode. Sources in the industry told IANS that the sand price has increased in the black market and that five units of river sand has increased from Rs 25,000 to Rs 45,000 after shortage of river sand. /IANS