A court hearing began in South Africa Friday, pitting an influential AIDS lobby group against a doctor who claims his vitamin therapies are more effective against AIDS than anti-retroviral drugs.

Treatment Action Campaign, or TAC, is asking the Cape Town court to order Dr. Matthias Rath to stop making defamatory comments about the lobby group.

The German-born doctor calls TAC a front for drug companies. He also claims AIDS drugs are toxic, saying the deadly disease can be treated successfully with nutrients.

The World Health Organization has condemned Dr. Rath, saying his claims are unhelpful and dangerous.

TAC successfully pressured the South African government to roll out a comprehensive program - including free drugs - to treat AIDS patients.

Some information for this report provided by AFP and AP.