A human rights group says it is concerned about "continuing abuses" at diamond mines in Zimbabwe.
This follows a last-minute decision by Zimbabwean authorities to halt a three-day sale of about 300,000 carats of rough diamonds.
Global Witness says some mines remain in the hands of the military despite an agreement with international monitors.
Insiders have told the BBC that the sale was only halted after "blood diamond" trade monitors intervened.
"We're obviously pleased that this auction has been cancelled but overall we're still concerned about the situation in the diamond fields in Marange," Global Witness' Anne Dunnebacke told the BBC Network Africa programme.
Senior Zimbabwe's mines ministry official Thankful Musukutwa on Thursday told a news conference in Harare that the auction had been stopped because it had not been approved by the Kimberley Process (KP), set up to regulate the trade in "blood diamonds" - those mined in conflict zones.
http://news.bbc.co.uk/2/hi/africa/8448335.stm