Washington (CNN) - The House Ethics Committee announced Friday that it is looking into potential ethics violations by Minnesota Republican Rep. Michele Bachmann and three other House members. The announcement came after a non-partisan panel referred a number of cases to the committee last month for further investigation.
In all four cases announced Friday the Ethics panel said it was taking the next step to investigate matters that were already probed by the outside panel, the Office of Congressional Ethics (OCE).
Bachmann's attorney acknowledged in March that the OCE was reviewing allegations about the improper transfer of campaign funds by her 2012 presidential campaign.
On Friday her attorney reiterated that the investigation would find that Bachmann did not do anything inappropriate.
"Today's statement by the House Ethics Committee emphasizes that its customary 45-day extension does not 'indicate that any violation has occurred, or reflect any judgment on behalf of the Committee.' It does not speak to the merits of this matter, and any inference to the contrary is false. We are confident the Committee will discover, upon proper review, that the highly politicized allegations made at the OCE level were baseless and without merit," William McGinley said in a written statement provided to CNN.
Massachusetts Democratic Rep. John Tierney was accused of violating rules involving public disclosure on his personal financial forms over the last three years, after his wife received several gifts. The ethics committee said it was reviewing his case.
Tierney released a written statement Friday saying these were old allegations involving items from his wife's brother who was thanking his wife for caring for their sick mother and his three children.
"While political opponents have spent millions of dollars to twist the facts and distort the truth for their own gain, I appreciate that the Ethics Committee has not prejudged the matter. I hope the Committee will expedite its review and I am confident it will find the allegations meritless as they have no foundation in law or fact," Tierney said.
The ethics committee also stated that it is also investigating New York Democratic Rep. Tim Bishop. During the last election Bishop came under fire for allegations that he solicited a $5,000 campaign donation from a supporter in return for helping the family get a permit to set off fireworks at their son's Bar Mitzvah celebration.
In a statement released by his office, Bishop stated, "As I have said many times, I welcome a fair-minded review of the facts because I have done nothing wrong."
A top House Republican leader, Illinois Rep. Peter Roskam, was also investigated by the outside ethics panel for a trip that he and his wife took in the fall of 2011 to Taiwan. House rules ban travel paid for by foreign governments.
Roskam's spokeswoman Stephanie Kittridge explained in a statement that the ethics committee itself approved of the trip and argued the OCE was wrong to review the matter that went through appropriate channels.
"The record reflects that Rep. Roskam fully complied with all laws, rules, and procedures related to privately sponsored travel. The trip was vetted and approved by the House Ethics Committee, the body legally authorized to make determinations on Congressional conduct," Kittredge said.
Kittridge added, "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."
The Office of Congressional Ethics is a separate entity set up in 2008 as a nonpartisan panel to screen potential instances of misconduct by members of the House of Representatives. If OCE decides a matter warrants additional review if can refer it to the House Ethics Committee, which determines whether an official investigation will be launched.
In all four cases the Ethics committee is required to reveal whether it is continuing to review cases that are sent to them within 45 days, unless they are dropped. These four cases were sent to the committee last month, and the next step of any investigation would involve the full ethics committee voting to empanel a group of its members to launch a formal probe. The committee could also decide to dismiss the matters if it decides there were no violations of House rules.
In Bachmann's case, since she has already announced she will retire at the end of her term, it's unclear whether the committee would complete any investigation before she leaves the Congress.
The committee statement in each case said it would announce its "course of action" on or before September 11, 2013.