Activist groups seeking to eradicate trade in conflict diamonds say that the global "conflict-free" certification scheme established in 2003 still has loopholes. The groups point to Zimbabwe and the Ivory Coast in particular, as well as to Venezuela, which does not participate in the Kimberley Process certification program.

Activists say that conflict diamond trade is rebounding in Sierra Leone, Liberia, the Ivory Coast, and Venezuela, and are calling for reforms to the Kimberley Process.

The issue of conflict diamonds has come in for heightened scrutiny since the human rights situation in Zimbabwe's diamond fields first began to attract media attention. Zimbabwe will serve as the real test for the Kimberley Process, said Nadim Kara of the Partnership Africa Canada (PAC). Kara said that political will was "being sapped by the incredible economic potential" of the Marange diamond fields, where right activists allege that security forces have killed hundreds of illegal prospectors.

Activists fighting trade in conflict diamonds saw the recent high-profile testimony of model Naomi Campbell, who was accused of receiving conflict diamonds from representatives of former Liberian president Charles Taylor in 1997, as an indication that the certification process was imperfect.

No one can be sure they are buying a conflict-free diamond, said Elly Harrowell of Global Witness, one of the groups that are fighting trade in conflict diamonds. Harrowell cited weak implementation, lack of political will on the part of governments, and "imperfect oversight and enforcement" as factors that facilitate illegal trade.

The diamond industry is aware of the problem posed by conflict diamonds. World Diamond Council President Eli Izhakoff said that conflict diamonds accounted for less than 0.2% of the total volume of diamonds traded. "Virtually today there are no conflict diamonds traded," Izhakoff said.

The Rapaport diamond company has taken a firm stance against trading diamonds from Zimbabwe, warning its members that doing so would cause them to be expelled from the Rapaport network. Rapaport is also concerned with imperfections in the KP scheme, saying that "There is no guarantee that diamonds with KP certifications are free of associations with human rights violations."

However, not everyone sees conflict diamonds as a major issue. Jack Jolis, a rough diamond consultant, wrote in the Wall Street Journal that there was no connection between diamonds and African wars, some of which, he noted, are carried on without any connection to diamond production.