The New Zealand Labour MP Charles Chauvel says the country's migrant policy discriminates against seasonal workers with HIV.
A report issued by the United Nations Global Commission on HIV and the Law has found that punitive laws are fuelling the AIDS epidemic.
At present, seasonal workers must provide the results of an HIV test, and those who test positive are automatically excluded from the scheme.
Mr Chauvel says this is adding to the problem.
"What that does in the places where we recruit our migrants from is it drives the people who ought to be going for testing and treatment and prevention underground because they know that if they get tested under the migrant scheme and get a positive result, that will be known, they'll be excluded and they'll suffer all the consequences."
Charles Chauvel is calling on the New Zealand government to change the law and let those who test positive into the scheme.