Sri Lankan market regulator,Securities and Exchange Commission (SEC),has launched an investigation into the National Savings Bank's purchase of 13 per cent stake in The Finance Company (TFC) for a par value of SLR 50 when the market value was hovering around SLR 30,officials said. It has been alleged that an individual holds positions as a director at both TFC and the brokering company for the deal. "We are looking at the possibility of insider trading",an SEC source said. The opposition has cried foul over the transaction which they claim had cost the exchequer about SLR 1.5 billion rupees. The leading trade chamber urged action to ensure integrity and transparency in stock trading. "Integrity and transparency are vital to maintain investor confidence",the chamber said. The NSB stated the board had decided to stop the payment due on the deal. The opposition law maker and economic expert Harsha de Silva expressed concern over the issue. "NSB is not just another bank. The number of savings accounts at NSB is 16. 7 million when the country's population is 20 million. Every account is guaranteed by the government. This is public money",he said. The Finance Ministry in its response said that NSB had been advised to refrain from moving away from its core activity.