Federal prosecutors on Friday said Sidley Austin partner James Cole, a former deputy U.S. attorney general, should be barred from representing the Chinese telecom giant Huawei Technologies because of his role in an unspecified investigation during his tenure in the Obama administration.

“Despite the obvious conflict of interest presented by Cole’s representation of [Huawei] in a prosecution by the United States when he previously represented the United States with respect to” the earlier investigation, “Cole has refused to recuse himself from this matter,” prosecutors said in a brief filed in the U.S. District Court for the Eastern District of New York.