The Washington Post reports that the Obama Administration has gathered evidence of Chinese companies helping Iran develop its nuclear program and missile technology. One American official associated with the investigation said the companies may be acting without knowledge of the Chinese government.

United Nations sanctions restrict international companies from investing in Iran’s nuclear and weapons programs. If the allegations are true, Chinese businesses are in violation of these sanctions but it is unclear how they might be punished.

American officials provided a “significant list” of Chinese companies and banks still doing business in Iran during a visit to Beijing last month. Washington faces a serious challenge in persuading China to wind down investments in the Iranian energy sector. Along with India, it would seem that China is trying to work around the sanctions to continue to do business in Iran.

To make matters worse, a special United Nations investigative panel presented a report on Darfur to the Security Council that shines light on a potentially illegal weapons trade between Beijing and Khartoum. The current round of sanctions prohibits the Sudanese government from importing weapons for its military campaign in the Darfur region. Recently, however, investigators discovered Chinese bullet casings at the sites of numerous attacks against international peacekeepers.

Beijing vehemently denied allegations that its weapons are being used in Darfur and has insisted that the report be rewritten.

Under the current sanctions regime, Sudan is permitted to import weapons as long as they are not employed in the Darfur campaign. As expected, the government in Khartoum has repeatedly skirted the rules.

Investigators told the Security Council that Sudanese forces have used more than a dozen type of Chinese ammunition against rebels in Darfur. Unidentified assailants also used Chinese bullets during several recent attacks on peacekeepers. These munitions have fueled a bloody conflict in which over 300,000 people have been killed and almost three million driven from their homes.