The UN Security Council has received a controversial report on violations of the Darfur weapons embargo, after weeks of delays due to objections by China.
The confidential report, which was leaked, says Chinese bullets have been found in Sudan's conflict-torn region.
The document does not say Beijing is necessarily responsible.
But it suggests China is not doing enough to ensure arms it sells to Khartoum do not end up in Darfur. The Chinese have criticised the report.
They say it is vaguely worded and full of flaws.
Beijing had previously refused to allow the Security Council's Sudan Sanctions Committee to formally pass the report to council members.
Ceasefires and peace negotiations have failed to end the conflict in the volatile western Sudanese region.
Close allies
The report, written by a panel of experts, was handed to British Ambassador Mark Lyall Grant, who currently presides the Security Council.
According to the leaks, it says a dozen varieties of bullet casings found in Darfur bore markings indicating the ammunition had been manufactured in China.
The BBC's Barbara Plett at the UN in New York says the allegations are controversial, but adds that China has the right to sell munitions to Khartoum as long as they are not used in Darfur.
The panel of experts has previously claimed that large amounts of foreign arms and ammunition are being trafficked into Darfur, fuelling the conflict between the government and rebel groups.
It was not immediately clear if the report would be made public.
Sudan and China are close allies - Beijing has played a key role in developing Sudan's oil industry.
The UN says that about 300,000 people have died and more than 2.6 million displaced by fighting since rebels took up arms in the region in 2003.
Sudan's President Omar al-Bashir is wanted by the International Criminal Court on charges his forces committed war crimes in Darfur - allegations he denies.
His government says the number of casualties in the Darfur conflict has been exaggerated for political reasons and the real figure is about 10,000.
