Story highlights A spokesman for Mueller told CNN that Mueller did litigation work last year for IronBridge

It's not clear whether the legal work for IronBridge would constitute a conflict for Mueller's handling of the Flynn investigation

Washington (CNN) Special Counsel Robert Mueller briefly did some legal work for a company that was part of a Middle East energy and arms project pushed by Michael Flynn, the former Trump national security adviser who Mueller is now investigating as part of the Russian meddling probe.

A spokesman for Mueller told CNN that Mueller did litigation work last year for the entity, called IronBridge, while Mueller was a partner at the WilmerHale law firm. He said the IronBridge work wasn't listed in Mueller's ethics disclosure form released last month by the Justice Department because it didn't meet the threshold for which disclosure is required. Mueller's filing listed multiple major legal clients including Facebook, Apple, Sony Pictures and the National Football League.

"The reporting requirement for public financial disclosure reports requires that you report any source that paid more than $5,000 for your personal services in any calendar year," said Peter Carr, a spokesman for the Special Counsel. "In June 2016 while at Wilmer Hale, Mr. Mueller spent less than half an hour on an IronBridge litigation matter that was handled by another partner. That amount did not meet the reporting requirement."

An attorney for Flynn declined to comment.

IronBridge was one of several consulting companies that were working on the proposed business deal, partnering with the Saudi government and Rosatom, Russia's government-run nuclear energy agency, to build nuclear energy plants in Saudi Arabia.

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