Restrictions on the sale of "blood diamonds" could soon go beyond conflict countries to include human rights abusers.

The two-day World Diamond Council conference, to be held in St Petersburg, Russia, this week, has dedicated a full day to the reported human rights abuses in Zimbabwe's diamond industry.

The outcome of this conference could lead to changes in minimum requirements for the 75 countries that are signatories to the Kimberley Process.

Abbey Chikane, the Kimberley Process monitor and former SA State Diamond Trader chief executive, said the changes in certification requirements would have an impact, not only on Zimbabwe, but on several other countries he would not name.

In November last year, members of the Kimberley Process Certification Scheme met for an annual plenary session to determine the way forward on Zimbabwe.

"We should reach some decision in St Petersburg," Chikane said. "But we will have to wait until this year's Kimberley Process plenary meeting, to be held in Tel Aviv in November, before any changes to the certification requirements can be changed."

But until then, some intervention will be needed.

Of all diamond-producing countries, only Ivory Coast and Argentina have chosen to withdraw from the Kimberley Process.

Despite this, Chikane said 99.3% of global trade in the precious gem was legitimate.

"Since we started (the Kimberley Process) in 2003, the three countries which were problematic - Sierra Leone, the Democratic Republic of the Congo and Angola - have since stopped trading in conflict diamonds, and have realised revenue from rough diamonds," he said.

"The money is now being used for education, health and other social infrastructure that was desperately needed."

While Zimbabwe's diamond production is a small fraction of the $8.5-billion of Africa's total production, certification for the economically depressed nation is crucial as this is one of the few remaining cash-generating industries.

The country has about $1.7-billion in diamond stockpiles which can't be sold legitimately, in line with the Kimberley Process requirements.

Various diamond mines and production facilities in Zimbabwe, particularly the Marange fields, have come under scrutiny over reported forced labour, rape, smuggling and other crimes.

Since the diamond incursion in 2006, there has been an influx of panners and illegal traders, leading to calls for the Zimbabwean police and army to occupy the area.

In May this year, Chikane met with senior Zimbabwe National Army and Zimbabwe Republic Police commanders.

They told Chikane that, following various operations, illegal diggers continued to encroach into the Marange area, despite the presence of dog units and closed circuit TV cameras.

"We have made a plea that the soldiers and the police should be withdrawn, and the government agrees," he said.

"But the challenge is that if we withdraw the army and the police, the diamond fields will be left unattended.

"The strategy that has been accepted is that Zimbabwe should attract as many investors as possible - large, medium and small producers. Because they'll be generating revenue, they'll be able to protect the area. The government doesn't have the money." Times Live