UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13D UNDER THE SECURITIES EXCHANGE ACT OF 1934 GigaMedia Limited -------------------------------------------------------------------------------- (Name of Issuer) Ordinary Shares, par value NT$10 per share -------------------------------------------------------------------------------- (Title of Class of Securities) Y2711Y104 -------------------------------------------------------------------------------- (CUSIP Number) -------------------------------------------------------------------------------- Winston Hsia Hoshin Gigamedia Center Inc. 14F, 122, Duenhua N. Road Taipei, Taiwan (886-2) 3518-1102 -------------------------------------------------------------------------------- (Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications) April 2, 2003 -------------------------------------------------------------------------------- (Date of Event which Requires Filing of this Statement) If a filing person has previously filed a statement on Schedule 13G to report the acquisition which is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(b)(3) or (4), check the following box |_|. NOTE: Six copies of this statement, including all exhibits, should be filed with the Commission. See Rule 13d-1(a) for other parties to whom copies are to be sent. *The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page. The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). (continued on following pages) Page 1 of 5 pages. --------------------- ----------------- CUSIP NO. Y2711Y104 13D PAGE 2 OF 5 PAGES --------------------- ----------------- ------------------------------------------------------------------------------- 1. NAME OF REPORTING PERSONS S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS Robustos Capital Investments Ltd. ------------------------------------------------------------------------------- 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [ ] (b) [ ] ------------------------------------------------------------------------------- 3. SEC USE ONLY ------------------------------------------------------------------------------- 4. SOURCE OF FUNDS AF ------------------------------------------------------------------------------- 5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e) [ ] ------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION The British Virgin Islands ------------------------------------------------------------------------------- NUMBER OF 7. SOLE VOTING POWER SHARES 0 BENEFICIALLY -------------------------------------------------------------- OWNED BY 8. SHARED VOTING POWER EACH 4,616,389 REPORTING -------------------------------------------------------------- PERSON 9. SOLE DISPOSITIVE POWER WITH 0 -------------------------------------------------------------- 10. SHARED DISPOSITIVE POWER 4,616,389 ------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4,616,389 ------------------------------------------------------------------------------- 12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES [ ] ------------------------------------------------------------------------------- 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 9.20% ------------------------------------------------------------------------------- 14. TYPE OF REPORTING PERSON CO ------------------------------------------------------------------------------- --------------------- ----------------- CUSIP NO. Y2711Y104 13D PAGE 3 OF 5 PAGES --------------------- ----------------- ------------------------------------------------------------------------------- 1. NAME OF REPORTING PERSONS S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS Leslie Koo ------------------------------------------------------------------------------- 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) [ ] (b) [ ] ------------------------------------------------------------------------------- 3. SEC USE ONLY ------------------------------------------------------------------------------- 4. SOURCE OF FUNDS PF ------------------------------------------------------------------------------- 5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e) [ ] ------------------------------------------------------------------------------- 6. CITIZENSHIP OR PLACE OF ORGANIZATION Taiwan, Republic of China ------------------------------------------------------------------------------- NUMBER OF 7. SOLE VOTING POWER SHARES 0 BENEFICIALLY -------------------------------------------------------------- OWNED BY 8. SHARED VOTING POWER EACH 4,616,389 REPORTING -------------------------------------------------------------- PERSON 9. SOLE DISPOSITIVE POWER WITH 0 -------------------------------------------------------------- 10. SHARED DISPOSITIVE POWER 4,616,389 ------------------------------------------------------------------------------- 11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4,616,389 ------------------------------------------------------------------------------- 12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES [ ] ------------------------------------------------------------------------------- 13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 9.20% ------------------------------------------------------------------------------- 14. TYPE OF REPORTING PERSON IN ------------------------------------------------------------------------------- Robustos Capital Investments Ltd., a British Virgin Islands corporation ("Robustos"), and Leslie Koo, a citizen of Taiwan, the Republic of China (Robustos and Leslie Koo are herein after referred to as the "Reporting Persons"), hereby file the statement with respect to the Ordinary Shares, par value NT$10 per share (the "Ordinary Shares"), of GigaMedia Limited, a Singapore corporation, (the "Issuer"), beneficially owned by them. Item 5. Interest in Securities of the Issuer. On February 20,2003 Robustos, a British Virgin Islands corporation, acquired 4,616,389 shares of Ordinary Shares at US$0.87 per purchased share pursuant to Regulation S. As of the date of the filing of this Statement, Robustos beneficially owns, and Leslie Koo may be deemed to beneficially own through Robustos, 4,616,389 shares of Ordinary Shares, which represents approximately 9.20% the outstanding Ordinary Shares based upon 50,154,000 shares of Ordinary Shares reported as outstanding as of June 30, 2002, in the Issuer's Form 20-F report for the year ended December 31, 2001. Page 4 of 5 pages. SIGNATURE After reasonable inquiry and to the best of its knowledge and belief, the undersigned certifies that the information set forth in this statement is true, complete and correct. Dated: April 2, 2003 Robustos Capital Investments Ltd. By: /s/ Cheng-hsiung Chiang ------------------------------ Name: Cheng-hsiung Chiang Title: Director LESLIE KOO /s/ LESLIE KOO ---------------------------------- Page 5 of 5 pages.