One option for international whistleblowers: The Foreign Corrupt Practices Act. The act prohibits corporations, both U.S. and international, from paying bribes to foreign officials and offers rewards. Click here to read the FCPA in English and 14 other languages.
From the National Whistleblower Center:
In a major breakthrough for international whistleblowers, on July 21, 2010n President Obama signed legislation that permits whistleblowers, including foreign nationals, to apply for monetary rewards based on reporting bribery prohibited under the Foreign Corrupt Practices Act (FCPA). The Dodd-Frank Wall Street Reform and Consumer Protection Act mandates that the U.S. Securities Exchange Commission (SEC) pay whistleblowers monetary rewards if they provide the U.S. government with information that leads to the successful enforcement of the FCPA. The act is applicable even if bribes are paid in a foreign country and the whistleblower is a foreign national.
The Whistleblowing International Network offers this list of activist groups.
The work of not-for-profit NGOs has been vital to ensuring whistleblowers are supported in individual cases, and better protected in law and policy in many jurisdictions. Some whistleblowing NGOs provide services in the form of early confidential advice, legal advocacy and casework, or mutual support and counselling. Others focus on public education and raising awareness, campaigning for legal reform and policy work, and still others offer training and seminars to employers, governments, regulators, judges, and other NGOs. Each contributes in its own way, many combine a number of these activities and most have to make choices based on doing as much as they can as effectively as they can with few resources to do it.
Government Accountability Project, USA
Protect (formerly Public Concern at Work), UK
Whistleblower-Netzwerk e.V. / Whistleblower-Network, Germany
Open Democracy Advice Centre, South Africa
Pištaljka (“The Whistle”), Serbia
Transparency International Ireland, Ireland
Commonwealth Human Rights Initiative, India
Centro de Derechos Humanos, Chile
Centre for Free Expression Whistleblower Initiative, Ryerson University, Canada
Oživení, Czech Republic
WB, Czech Republic, Czech Republic
Accion Ciudadana, Guatemala
Transparency Estonia, Estonia
Information Clearinghouse Japan, Japan