Russia condemned what it called a push to "politicise" its diamonds over the conflict in Ukraine and said attempts to question its compliance with the international diamond certification scheme were "totally unfounded" and "far-fetched".

The Kimberley Process, a coalition of governments, the diamond industry and civil society responsible for certifying diamonds as conflict-free, is split over a push by Ukraine and others to expand its definition of conflict diamonds to include those funding aggression by states.

The KP Civil Society Coalition (CSC) and some member states sought to discuss whether Russia's diamonds were helping to fund the war in Ukraine during a KP meeting in Botswana last week.

"The Russian Federation absolutely condemns the orchestrated attempts of CSC, backed by absolute minority of some Western participants, to politicize the work of the Kimberley Process by deliberately distorting or even openly replacing its basic principles," Russia's finance ministry said in an emailed statement. It did not specify which principles it felt were being distorted or replaced.

The CSC did not immediately respond to an emailed request for comment.

The KP defines conflict diamonds as those that fund rebel movements seeking to overthrow legitimate governments, a narrow definition that many have sought to widen since the KP was founded in 2003.

Russia, which was KP chair last year, has "championed" work on revising the definition of conflict diamonds for the past five years, the finance ministry said, and it is committed to continuing talks on the definition.

"We therefore call on our opponents to refrain from further speculative accusations, abstain from political demagoguery and concentrate on the substantive work of the KP," the finance ministry said.

The KP makes all decisions by consensus and the rift over Russia and Ukraine could jeopardise its effectiveness.