Senior Labour Party MP Charles Chauvel has been appointed to a new United Nations commission set up to investigate laws that adversely affect Aids sufferers.
The Global Commission on HIV and the Law was launched in Geneva today.
Mr Chauvel is one of 14 commissioners charged with providing global leadership on HIV-related legal and human rights issues.
Among his fellow commissioners are former presidents of Brazil and Botswana, a US Congresswoman, a former Thai senator and leading international human rights activists.
"The Aids response is increasingly undermined by human rights violations," the UN said today.
"There are numerous reports from across the globe of the negative impacts of punitive laws, policies and practices on national Aids responses including escalating stigma, reduced access to health, legal and social services, and increasing HIV risk and vulnerability."
Former prime minister Helen Clark, who now heads the UN Development Programme, was at the launch.
The commission will meet three times over 18 months between now and December 2011.
Mr Chauvel is Labour's spokesman on climate change and energy. He has a legal background and was chairman of the New Zealand Aids Foundation in 1995.