Several D.C. council members were subpoenaed last week as part of a U.S. Attorney’s Office investigation into campaign contributions by prominent D.C. businessman Jeffrey Thompson.

Thompson, who has long been among the top political fundraisers in the District, has come under scrutiny for possibly circumventing campaign finance laws through “straw donations,” or giving money to a third party who then submits the donation under his own name.

Thompson’s home and offices were searched by federal agents last month as part of the investigation. At the time, Ralph B. Bazilio, the chief operating officer of Thompson’s firm, Thompson, Cobb, Bazilio & Associates, told The Washington Post that there had been no accusation of wrongdoing. He added that the firm had turned over all relevant documents to the attorney’s office.

Last week, council members Jack Evans (D-Ward 2), Phil Mendelson (D-At-large) and Yvette M. Alexander (D-Ward 7) each confirmed their campaign treasurers have received subpoenas and are cooperating fully with the investigation.

Mendelson, who most recently confirmed having received a subpoena, issued a statement listing the contributions he had received from Thompson during his 2010 campaign.

“I regret that this has created yet another controversy around city hall. I believe disclosure is the best course. I am hopeful that the U.S. Attorney’s investigation will uncover the facts as quickly as possible,” he said in the statement.

Wesley Williams, spokesperson of the D.C. Office of Campaign Finance, said that his office did not have any additional information and had not been subpoenaed.

The U.S. Attorney’s Office also declined to comment because the investigation is ongoing.