The nation's securities watchdog has dispatched investigators to Switzerland to search for evidence that Livedoor group conducted money-laundering, unnamed sources said Friday.

The Securities and Exchange Surveillance Commission is also planning to send officials to Hong Kong and the British Virgin Islands, a known tax haven, to shed light on whether Livedoor used overseas financial institutions and companies to conduct dubious securities transactions, the sources said.

The Livedoor group is believed to have used accounts at Swiss and Hong Kong banks, and companies in the Virgin Islands, to deposit gains from sales of its shares it handed over to takeover target firms, which were in fact under control of the group's investment partnership. Such money is believed to have been later transferred back to the parent company.