Updated: 11:42 a.m.

The Office of Congressional Ethics announced Thursday that it will not publicly release evidence gathered during its probe into Members’ ties to the now-defunct PMA Group lobbying firm, instead forwarding the documents to the Justice Department.

The move raises questions over whether the OCE believes campaign donations may have influenced the appropriations process.

“The evidence pertains to a factual finding by the OCE Board that certain persons and companies saw their campaign donations as affecting decisions about earmarks,” the OCE said in a written statement. “The Board released this information to the Department of Justice.” But the OCE declined a request from Reps. Jeff Flake (R-Ariz.) and Paul Hodes (D-N.H.) to publicly release the PMA evidence.

The OCE, which reviews potential rules violations and refers investigations to the ethics committee, last year probed seven Members and their ties to PMA. It suggested dismissal of five of those cases and recommended further review of two.

The Committee on Standards of Official Conduct, commonly known as the ethics panel, reviewed the OCE’s probe and issued a report in February declaring that no Member of the House and no House staffer had acted inappropriately in providing earmarks to companies that had hired PMA to lobby on their behalf.

Flake and Hodes, concerned about the breadth of the panel’s investigation, asked the OCE to turn over all of the documents that it had collected.

“The OCE Board is committed, consistent with the limits prescribed by House Resolution 895, to keep Members and the public informed about its work,” the OCE letter states. “However, under the circumstances of this case and the risk of prejudice to any pending criminal investigation, among other concerns, the Board was unable to grant their request.”

The ethics committee similarly rejected Flake’s demands for the panel to detail its investigation earlier this month, asserting that doing so could have a chilling effect on future investigations.

Flake had sponsored numerous resolutions calling for a public account of the investigation, citing language in the ethics committee’s PMA report that acknowledged a “widespread perception” among lobbyists that campaign contributions increased access to Members and influence over earmarks.

Flake acknowledged Thursday that he was disappointed the documents would not be released, but he added: “The last thing I want to do is prejudice any criminal investigations that are going on.”

The Arizona lawmaker has also called for new guidance from the ethics committee on the appropriations process, particularly with regard to earmarks, but the panel indicated in a public statement in April that it will not do so.

“In addition, we note that policy decisions — whether about the current appropriations process, including earmarks, or about the campaign finance system — are not within the jurisdiction of the Committee. Whether these policies should be changed is a subject that should be taken up in the appropriate venue,” ethics panel Chairwoman Zoe Lofgren (D-Calif.) and ranking member Jo Bonner (R-Ala.) said in an April 26 statement.

Nonetheless, Flake said Thursday that he will continue to pursue new guidance from the ethics panel. He declined to detail his plans but said: “There are a few ways we can put some pressure on, and I think we need to do it.”

The OCE’s Thursday announcement cited that April 26 statement as part of the OCE board’s decision to forward the information to the Justice Department.

“The Board made the referral to the Department of Justice at this time after the Committee on Standards of Official Conduct apparently completed its review of the evidence (evidence previously provided to the Standards Committee by OCE) and the Chair and Ranking Member of the Committee issued a statement” in response to the Flake resolutions.

The OCE board is chaired by ex-Rep. David Skaggs (D-Colo.) and co-chaired by ex-Rep. Porter Goss (R-Fla.).

The FBI this week released documents related to the late Rep. John Murtha, who was one of the Members close to PMA, which was investigated by the OCE. The FBI said some documents related to the Pennsylvania Democrat were being withheld because an investigation is still ongoing and the documents that were released related to earmarks that Murtha had obtained.