Windhoek - Calls for an international ban on Zimbabwe's diamond sales are set to dominate this week's meeting of the global body set up to prevent trade in "blood diamonds", in a key test for the regulatory regime.
Civil society groups who form part of the Kimberley Process are demanding the suspension of Zimbabwe's international diamond trade, citing human rights abuses in the eastern Marange diamond fields.
A Kimberley investigation in July documented "unacceptable and horrific violence against civilians by authorities" in Marange, following months of reports of killings, forced evictions and other abuses by the army in the region near the Mozambican border.
The Kimberley Process, named for a South African mining town, was created in 2003 with the aim of curbing the flow of "blood diamonds" into the mainstream market.
About 70 diamond-producing countries, industry groups and civil society organisations form part of the Kimberley Process, which is meant to stop diamond sales from benefitting armed groups.
In Zimbabwe's case, the military has taken control of the Marange fields, which is believed be an important source of revenue for President Robert Mugabe's ZANU-PF party, according to a report by Human Rights Watch.
Global Witness, which monitors exploitation of natural resources, said Zimbabwe is in violation of Kimberley Process rules - even though its diamond sales aren't funding a war.
"You have a situation in which the exploitation of diamonds is accompanied by and very directly linked to human rights abuses which the Kimberley Process was designed to prevent," campaigner Mike Davies told AFP.
But countries like Namibia, chairing the four-day meeting that opens Monday in the coastal town of Swakopmund, have so far opposed suspending Zimbabwe.
After the Kimberley investigation, Namibia made its own mission to Zimbabwe and indicated that suspension was not an option - only to be reprimanded by fellow members of the process for acting without the group's mandate.
For Zimbabwe, the talks come at a critical point for Mugabe. Two weeks ago Prime Minister Morgan Tsvangirai, his partner in a teetering unity government, suspended cooperation with Mugabe, drawing regional concern about the country's fate.
Namibia, however, now faces pressure to agree to suspend Zimbabwe or risk undermining the effectiveness of the entire diamond control regime, said Human Rights Watch researcher Dewa Mazhinga.
"Namibia is quite close... to Mugabe, but they are also under serious pressure because the credibility of the Kimberley Process is at stake. This could be make or break for the Kimberley Process," he said.