LONDON (Reuters) – A former Swiss private banker handed over data on hundreds of offshore bank account holders to WikiLeaks founder Julian Assange at a news conference on Monday.

Rudolf Elmer once headed the office of Julius Baer in the Cayman Islands until he was fired by the bank in 2002. He is scheduled to go on trial in Switzerland on Wednesday for breaching bank secrecy.

Elmer handed Assange the data at a news conference at a media club in London. The two yellow and blue discs contain information on 2,000 banking clients who have parked money offshore.

“He (Elmer) is clearly a bona fide whistleblower… We have some kind of duty to support him in that matter,” said Assange, who is on bail in Britain and fighting extradition to Sweden where he faces questioning over alleged sex crimes.