ActionAid has hit a major stumbling block in its bid to stop the trade in so-called conflict diamonds, the rough diamonds sold by rebel soldiers to fund conflicts in Africa.
The charity has been instrumental in pushing through the Kimberley Process, a new system of self-regulation by the diamond industry, which requires government enforcement to be effective.
But at the first plenary meeting of the Kimberley Process Certification Scheme, brokered by the UN, governments from across the world have delayed instituting a system of regular monitoring designed to prevent abuses of the new scheme.
The charity is "deeply disappointed" by the failure of delegates to introduce official monitoring.
"The credibility of the Kimberley Process rests on effective monitoring," said Bethan Brookes, external affairs officer at ActionAid. "Although we're not entirely surprised, we had really hoped for more progress. It's now essential that we continue to push forward."
Although the discussion has officially just been postponed until the next plenary meeting in October, the charity says that the delay could have serious implications for the scheme's future success.