A decision by the U.S. Treasury Department to approve the takeover of a Canadian energy firm by a front company for the Chinese government may have put millions of dollars in the pockets of influential backers of President Obama, according to a transparency watchdog group.

The $15.1 billion takeover of Nexen Inc. by the Chinese government-owned Chinese National Offshore Oil Corporation enabled CNOOC to drill for oil and natural gas in Canada and off the U.S. in the Gulf of Mexico.

"As a state enterprise, CNOOC is owned by the Chinese government and is managed by Communist Party officials. CNOOC offered Nexen a 60% premium over the stock's trading value at the time of the takeover, prompting analysts to describe the terms as 'a fantastic deal for Nexen.' It also raised questions as to whether the Chinese government's interests were more strategic than economic," according to Judicial Watch, the Washington-based activist non-profit devoted to increasing transparency in the daily operations of the federal government,

Judicial Watch filed a Freedom of Information Act request on Nov. 13, 2012, seeking Treasury documents related to the approval granted for the takeover by the department's Committee on Foreign Investments in the U.S. The government is required to respond to FOIA requests within 20 days after acknowleding receipt of an FOIA request, but Treasury officials failed to do so, according to Judicial Watch.

The CFIUS is chaired by the Secretary of the Treasury and its members include the Attorney General, the U.S. Trade Representative and the secretaries of the departments of defense, state, homeland security, commerce, and energy.

Judicial Watch filed an FOIA lawsuit in federal court on Feb. 14, but only announced the filing today.

Based on public records and media reports, however, Judicial Watch officials believe the documents it seeks are needed to assure taxpayers that the CFIUS approval was not influenced by political considerations and did not benefit campaign backers of the president. The group cited these examples in announcing its lawsuit of apparent conflicts of interest:

* Taconic Capital, which reported in its third quarter SEC filing that it had acquired six million shares of Nexen between July 1 and September 30, 2012. Taconic's founder and managing director is Frank Brosens, an Obama bundler who has raised more than $1 million for the President. Brosens was Timothy Geithner's first choice to run the TARP (Troubled Assets Relief Program).

* Farallon Capital Management LLC, which bought 8.7 million shares of Nexen (1.65 percent of the company) between July 1 and September 30, 2012. The founder of Fallon Capital is Thomas Steyer, is a long-time Democratic fundraiser who ridiculed Romney's energy plans at the 2012 Democratic National Convention.

* Eton Park Capital Management, which bought 6,737,000 shares (1.28 percent) of Nexen. Eton Park was founded and is directed by Eric Mindich, a bundler who raised more than $71,000 for Obama this cycle and has given more than $500,000 to Democratic candidates since 1990.

* D.E. Shaw & Co., which increased its position by 5.8 million to 6.5 million shares, or 1.22 percent of the company. D.E. Shaw was founded by David E. Shaw, an Obama bundler in the $200,000 to $500,000 range. He also sits on the President's Council of Advisors on Science and Technology, as he did under the Clinton administration.

* Covington & Burling LLP, in which Eric Holder was formerly a partner, was hired by Nexen to lobby on behalf of the acquisition's approval.

"With one ill-chosen action, the Obama administration has managed to undermine our strategic interests and reward its corporate cronies," said Tom Fitton, President of Judicial Watch. "It's little wonder that the Treasury Department is defying the open records law to stonewall accountability. And Americans may want to compare and contrast the quick approval of this Chinese strategic initiative with the Obama administration's scandalous delay of the related Keystone XL oil pipeline project."

A Treasury Department spokesman has been asked for comment on the Judicial Watch lawsuit.

Go here to read the Judicial Watch filing. More information is available here from Judicial Watch.

UPDATE: Treasury Department cannot comment

Holly Shuman, a Treasury Department spokesman, pointed out that "by law, information filed with CFIUS may not be disclosed by CFIUS to the public."

As a result, "the Department does not comment on information relating to specific CFIUS cases, including whether or not certain parties have filed notices for review," she said.