Global Witness has urged European Union (EU) foreign ministers to strengthen measures to restrict sales of diamonds from Zimbabwe's Marange region to Europe.
The call comes as Belgium pushes for sanctions against Zimbabwean diamond mining interests to be dropped.
"Global Witness' investigations point to a serious risk that diamond revenues could be used to fund violence in this year's election [in Zimbabwe]. The Belgian government is claiming concern for the Zimbabwean people; however its true interests are closer to home in the diamond markets of Antwerp," says Global Witness diamonds campaigner, Emily Armistead.
"EU members seeking to promote democracy and stability in Zimbabwe should avoid a ménage-à-trois with Belgium and its diamond dealers this Valentine's Day," she adds.
Global Witness claimed in a report last year that diamond revenues are providing financing to security forces controlled by the ZANU-PF party of President Robert Mugabe.
Sanctions against Zimbabwe are increasingly dividing opinion among EU states, the group said. "Whilst some members believe that restrictive measures should remain in place until Zimbabwe's elections later this year, the Belgian government is pressing for sanctions against the state-owned diamond company, Zimbabwean Mining Development Corporation (ZMDC), to be dropped immediately," Global Witness says in a statement.
Global Witness is calling for ZMDC to remain on the list of entities affected by restrictive measures and for another company, called Anjin, and Hong Kong-based businessman Sam Pa to be added to the list.