The anti-corruption bureau of the CBI has arrested a former and a current senior official of the Calcutta-based MSTC Ltd for allegedly colluding with jewellery exporters to cause a loss of Rs 464 crore to the public-sector undertaking.

Along with former chairman and managing director of MSTC Malay Sengupta, chief general manager Tapan Basu and a Delhi-based insurance consultant of the company, Shailendra Kumar Sinha, were arrested from Calcutta and New Delhi and produced before a special CBI court in Mumbai on Wednesday. They were remanded in police custody till May 10.

The arrests were made in connection with an October 2010 case of export fraud registered by the CBI against Shishir Dharkar, a former chairman of Pen Urban Co-operative Bank and a partner in export firm Space Mercantile, and five other gold exporters for duping MSTC of revenue to the tune of Rs 464 crore.

Six people had been arrested earlier in connection with the case.

“Investigations revealed that the six accused had entered into a criminal conspiracy with Sengupta, Basu, Sinha, and Utpal Sarkar, the deputy general manager of MSTC. The six exporters submitted forged and fake documents to MSTC for exporting gold jewellery to several buyers in the UAE. The three MSTC officials abused their official position as public servants to accept the forged documents and release 80 per cent of the export value to them,” said a CBI official.

A CBI team raided Sarkar’s residence on Saturday but could not find him.

“We had doubts about the roles played by Sengupta and Basu but did not find anything incriminating during the initial probe. Subsequent investigation showed that the duo were fully aware that the export documents were forged. The exporters not only exported jewellery to the UAE but also sold gold in the UAE open market for a two per cent commission,” said an official.

The CBI had earlier arrested Dharkar, who owns half the shares of Space Mercantile, his wife Gul Raihina Omer, Prem Kumar Sharma, an advisor to Pen Urban Co-operative Bank, consultant Rais Ahmed, Jayesh Desai of Joshi Bullion and Gems Jewellery, and Delhi-based consultant R. Mani.

CBI sources claimed that a team from Mumbai’s anti-corruption branch of the agency arrived in Calcutta on Saturday last and conducted raids in Kasba and other parts of south Calcutta on Sunday. The team seized some documents.