Chesapeake Energy Corp. disclosed in a filing late Wednesday that it has received subpoenas and demands for various documents in connection with an investigation launched last year regarding a Michigan leasehold sale.

In June 2012 the Michigan Department of Natural Resources disclosed that it had begun working with the state’s Attorney General to review allegations that Chesapeake and Encana Corp. had colluded to avoid competing in state lease auctions in 2010 (see Shale Daily,June 26, 2012). Reuters had pieced together emails obtained between Chesapeake officials, including former chief Aubrey McClendon, and Encana management and said executives discussed how to avoid bidding against each other in a 2010 auction.

In February, Michigan-based NorthStar Energy LLC filed a lawsuit alleging that Chesapeake, Encana and O.I.L. Niagaran LLC had conspired to rig the 2010 auction (see Shale Daily,Feb. 28). The lawsuit claimed that the anticompetitive agreement had the effect of forcing NorthStar to sell its leases at prices less than they were worth. NorthStar filed the lawsuit in U.S. District Court for the Western District of Michigan (NorthStar Energy LLC v. Encana Corp. et al, 1:13-cf-00200-PLM).

In its SEC filing, Chesapeake said it was subpoenaed on Sept. 16 by officials “relating to its investigation of possible violations of that state’s criminal solicitation law” in Michigan.

The latest subpoena is from the U.S. Department of Justice (DOJ) and “certain state governmental agencies,” for “subpoenas and demands for documents, information and testimony in connection with investigations into possible violations of federal and state laws relating to our purchase and lease of oil and gas rights,” Chesapeake said.

Chesapeake’s board of directors conducted an internal investigation of the matter last year and earlier this year said it had concluded that the company “did not violate antitrust laws in connection with the acquisition of Michigan oil and gas rights in 2010” (see Shale Daily,Feb. 21). An internal investigation by Encana also found no evidence of violations (see Shale Daily,Sept. 7, 2012).

Chesapeake said it is “providing information and testimony to the SEC pursuant to subpoenas and otherwise in connection with this matter and is also responding to related inquiries from other governmental and regulatory agencies and self-regulatory organizations.”