WikiLeaks founder Julian Assange is among 241 nominees for the 2011 peace prize. Photo: Reuters

New files about to be dumped onto the Internet by WikiLeaks contain embarrassing diplomatic cables that could harm Moscow's relations with Washington, the Kommersant newspaper reported on Friday.

The confidential cables contain general assessments of the political situation in Russia and “unflattering characteristics” of Russian leaders, the respected business daily reported citing a top source at the whistleblowing website.

“The documents include recordings of US diplomats' conversations with Russian politicians, assessments of Russia's most notable events, and analyses of what is happening in the country and in its domestic and foreign politics,” the newspaper wrote.

The foreign ministry has not been officially informed about an impending leak, although certain details about the files could have been passed on to Russian officials through the US embassy in Moscow, the newspaper wrote.

WikiLeaks has not said what will be contained in its coming release, indicating only that it will be “seven times” the size of the Iraq War logs in which it posted 400 000 secret documents.

US State Department spokesperson Philip Crowley said on Wednesday that the United States was concerned about the files' release.

“We are gearing up for the worst-case scenario, that leaked cables will touch on a wide range of issues and countries,” Crowley told AFP. -