The House Ethics Committee revealed Friday that it is reviewing the alleged misconduct of four members of Congress — two Republicans and two Democrats.

In four separate statements, Chairman K. Michael Conaway, R-Texas, and ranking member Linda T. Sánchez, D-Calif., jointly announced that the panel was reviewing matters relating to Congressional Tea Party Caucus Co-Founder Michele Bachmann of Minnesota and Chief Deputy Majority Whip Peter Roskam of Illinois, along with Democrats Timothy H. Bishop of New York and John F. Tierney of Massachusetts.

Next steps for all four cases will be announced on or before Sept. 11.

“The Committee notes that the mere fact of a referral or an extension, and the mandatory disclosure of such an extension and the name of the subject of the matter, does not itself indicate that any violation has occurred, or reflect any judgment on behalf of the Committee,” each statement reads.

The quasi-independent Office of Congressional Ethics referred all four cases to the Ethics Committee earlier this month, but only on Friday were the subjects of the cases made public. Neither entity would discuss the nature of the ethics inquiries, but previously published news reports provide some context.

Bachmann appears to be under scrutiny for a possible violation of campaign finance regulations, namely that she used funds from her leadership political action committee, MICHELE PAC, to pay for costs related to her failed 2012 presidential bid.

“There are no allegations that the Congresswoman engaged in any wrongdoing,” William McGinley, Bachmann’s attorney, said in a statement in late March. “We are constructively engaged with the OCE and are confident that at the end of their Review the OCE Board will conclude that Congresswoman Bachmann did not do anything inappropriate.”

Roskam is subject of an ethics probe into whether he accepted an “impermissible gift” when he and his wife traveled to Taiwan in October of 2011. Though the Ethics Committee approved the trip, the panel is now reportedly looking into whether the Chinese Culture University was truly the official sponsor, and not the Taiwanese government, which would be an ethics violation.

“The OCE is wrong to take issue with the involvement of the Government of Taiwan in planning and conducting the trip, a matter that is routine, allowed under the law, and was known to the House Ethics Committee as they thoroughly vetted and approved the trip,” said Roskam’s spokeswoman, Stephanie Kittredge, in a statement Friday. “Rep. Roskam will continue to fully cooperate, having already turned over every document and communication, made himself and his staff available for interview, waived his right to confidentiality with the House Ethics Committee, and otherwise provided any and all information regarding the trip to OCE.”

Kittredge noted that Roskam also “is taking the extraordinary step of voluntarily releasing the non-public OCE report and materials relating to their review. He fully expects the clear and indisputable facts of the case to speak for themselves, that both he and his staff have acted in accordance with all laws, rules, and regulations.”

Bishop has been the focus of ethics complaints for allegedly helping secure fireworks permits for a businessman who later donated $5,000 to his campaign, according to The Associated Press.

“As I have said many times, I welcome a fair-minded review of the facts because I have done nothing wrong,” Bishop said in a statement.

Tierney also released a statement in response to “the outlandish accusations made by his political opponents and Super PACs in the 2010 and 2012 elections over his personal financial disclosure reports.

“I welcome the opportunity to finally put this issue to rest after years of my opponents attacking me and my family,” Tierney said. “For more than three years they have tried repeatedly to misrepresent gifts my wife received from her brother in appreciation for caring for their dying mother and his three children who were without parental supervision. There is nothing new that has not already been reviewed in both a court of law and by the voters of my district who sent me back to Congress in two subsequent elections.”

According to news reports by the Boston Globe, Tierney was asked last year “about $223,000 that federal prosecutors said his wife received through a joint bank account she managed for her brother, Robert Eremian, a federal fugitive who was running an illegal gambling business from the Caribbean island of Antigua.”

The Globe reported Friday that Tierney and his wife, Patrice, have described the money through that account as “a gift from a relative that was exempt from requirements that Tierney disclose the source of the money on his annual financial disclosure form and report the money as income to the IRS.”