A bank that sold Lehman Brothers minibonds has offered to return an investor's money, a legislator said last night. Democratic Party legislator-elect Kam Nai-wai, who has been helping investors in the complex derivatives guaranteed by the bankrupt investment bank, said one investor had asked that their case be withdrawn from the list of those who needed help because a bank had offered to return the investor's money. The bank is believed to be Mevas Bank, one of 21 banks in the city said by the Monetary Authority to have sold the minibonds and similar products backed by Lehman Brothers, which was the fourth-largest investment bank in the US until its collapse 17 days ago. Mr Kam refused to say how much the case involved. Tens of thousands of Hongkongers have invested a total of HK$15.6 billion in the Lehman Brothers-backed derivatives, and face substantial losses. At the urging of some of them, the Monetary Authority has opened an investigation into whether the banks misled investors who bought them. The Securities and Futures Commission has launched its own investigation of three brokerages which sold them. The investors complain they were misled into thinking they were buying a form of corporate bond and were unaware until recently that the minibonds were guaranteed by Lehman Brothers. They accuse the banks of not fully disclosing the risk involved. The minibonds consist of high-risk derivatives such as synthetic collateralised-debt obligations (CDOs) and credit default swaps (CDS). They were marketed as proxy investments in well-known companies such as Hutchison Whampoa and HSBC. Mevas Bank denied a report in a Chinese-language newspaper that it had announced a refund for investors in the minibonds. An employee who answered a call to its customer services hotline said the bank had made no such announcement. A spokeswoman for Dah Sing Bank, which owns Mevas and also sold minibonds, could not be reached.