The Indian Bureau of Mines (IBM), a wing of the ministry of mines, has tracked down 21 of the 100 odd operative mines in the state for illegal mining.
Three of the mines are operated by the Vedanta Resources-owned Sesa Goa Ltd and another is owned by former Goa chief minister Shashikala Kakodkar.
Show cause notices issued by IBM accessed by IANS reveal the 26.77 hectare Sonshi lease operated by Sesa Goa Ltd, located 40 km from here, indicates that the firm extracted nearly double of the proposed 2.52 lakh tonnes of iron ore for the year 2009-10.
In 2009-10, it was proposed to produce 2.52 lakh tonnes of subgrade ore against which 4.04 lakh tonnes was produced, senior mining geologist S.K. Adhikari said.
Dayanand's mine has been suspended as its operations had stretched outside the stipulated lease area, said Deputy Controller of mines and IBM task force team leader G.C. Meena.
The mining extraction techniques were not scientific, he added.
Adhikari also pointed to other irregularities in yet another mine at Sanquelim, 35 km from here.
Sesa Goa Ltd had failed to implement greening of mining pits and also recovered 1.97 lakh tonnes of low-grade ore, which was not part of the approved mining plan, Adhikari said in his show cause notice.
According to the notice, reforestation had to be undertaken in Sanquelim mines.
In 2009-10, 11,493 saplings were supposed to have been planted in Macarxendo and 7,885 in Cancagalle. In 2010-11, 11,493 saplings were meant to be planted in Macarxendo and 1,100 in Cancagalle.
"But it was observed that no plantation has been taken up in these two leases of the mine during the previous two years," Adhikari stated.
Other mining outfits which have been hauled up for illegal mining are Rajaram Bandekar mines at Shigao, V.M. Salgaonkar Brothers also at Shigao, Sociedade Timblo Industries Limited at Suctoli, Shantilal and Kushaldas and bros at Joleracho Dongor, Chowgule and Co Ltd at Costi.
Meanwhile, Justice M.B. Shah's commission is probing unlawful mining in Goa, Orissa, Chhattisgarh, Andhra Pradesh and Karnataka.
His team has been camping in Goa -- visiting mining leases, interviewing bureaucrats and inspecting documents.
"We are depleting our national wealth only because of exports. I have already submitted a report on remedial measures which the (central) government can take to restrict illegal mining," Shah told reporters after a public hearing on illegal mining in Goa.
Opposition leader Manohar Parrikar has accused Chief Minister Digambar Kamat as well as several cabinet ministers of being a part of the scandal.
Goa exported nearly 54 million tonnes of iron ore in the last financial year. Parrikar has claimed that nearly 20 percent of it was from illegal mining.