Gandhinagar, March 7 (IANS) Robbers held hostage the family of an Indian diamond merchant in Belgium and freed them only after taking a vast amount of gemstones valued at millions of dollars, reports reaching here said.

The crime took place Saturday in Antwerp, the world's biggest diamond hub and reputedly a crime free zone.

Five to six armed men walked into the villa of Pankaj Maldar, who hails from Gujarat and heads the Rs.1,500 crore diamond firm Carp Impex NV. They took his wife and two children hostage.

The gang, who apparently had full details of the diamond stocks with Maldar's firm, called up Maldar at his office and demanded the diamonds in return for his family's safe release.

Left with no option, the distraught Indian handed over the diamonds. Some sources in Surat, India's diamond hub, estimated the value of diamonds at over Rs.100 crore.

Vasant Mehta, chairman of the Gems and Jewellery Export Promotion Council (GJEPC), said the industry would take up the issue with Belgian Crown Prince Philippe during his visit to India beginning March 25.

'It is easily one of the biggest diamond robberies in Belgium,' he said.

According to him, some 400 Indian families in Antwerp were involved in the diamond trade.

'Antwerp is perhaps the safest place in the world. This robbery has come as a very big surprise,' he added.