WASHINGTON -- The House's investigation of a page sex scandal has only one certainty: Former Rep. Mark Foley will escape punishment by his peers.

It is the Florida Republican's sexually explicit electronic messages to teenage former male pages that have ignited what has become a pre-election firestorm.

Congress only can punish current members, officers and employees. Foley resigned on Sept. 29, but is under investigation by federal and Florida authorities.

If the House ethics committee finds evidence of a Republican cover-up, many people could be in jeopardy, facing consequences that range from a mild rebuke in a committee report to a House vote of censure or expulsion.

Unlike the committee's usual practice of identifying the investigative target at the outset, this probe is wide open. Anyone who knew of Foley's salacious messages before the story broke at the end of September has reason for concern.

"At this point, what we're launching is an investigation into this whole affair, without a specific target," said California Rep. Howard Berman, the senior Democrat on the 10-member committee divided evenly among Republicans and Democrats.

"But because Mark Foley has left the Congress, we don't have the authority to discipline him in any way. The reason what happened is relevant is because there are people now who have responsibilities, and we're gathering the facts which are related to his conduct to make judgments," Berman said.

A second committee member, Rep. Judy Biggert, R-Ill., said House Speaker Dennis Hastert's prominence in questioning about who knew what and when about Foley's conduct toward pages and Hastert's closeness to her will not be problematic.

Hastert's leadership political committee gave Biggert $6,000 for her 2002 campaign and his re-election committee gave her $1,000. Her district also adjoins Hastert's.

"We're looking at a great number of people, not just one specific person," Biggert said. "The facts will lead to us to who, if there is someone, who perhaps did a cover-up."

Fred Wertheimer, president of Democracy 21, a group that monitors congressional ethics, wondered whether the committee can conduct an impartial investigation without an outside counsel.

The committee rejected that idea, as it has done occasionally in other high-profile cases involving House leaders.

"Published reports have clearly indicated a number of House members were aware of the incident with the House page," Wertheimer said, referring to less suggestive e-mails Foley sent to a former page from Louisiana. "You would expect the committee to make clear they would be looking at those members. That doesn't mean they would reach any conclusion."

He noted the committee did not specify who it will interview. Hastert has said he was not aware of Foley's inappropriate conduct until the story broke publicly late last month.

"The House ethics committee process is a secret process so we don't know what's going to go on," Wertheimer said.

The committee was in turmoil from the start of the current Congress in January 2005 through last May, when it finally announced a number of investigations.

Bitter partisan arguments broke out in early 2005 when Hastert, at the request of former Majority Leader Tom DeLay, replaced Republicans on the committee who had voted for reports critical of DeLay's conduct.

Then Hastert's hand-picked chairman, Rep. Doc Hastings, R-Wash., and the committee's top Democrat, Rep. Alan Mollohan of West Virginia, argued to a stalemate over staff and rules for investigations.

It was only after Mollohan -- under his own ethics cloud involving business deals -- stepped down from the committee that the partisan squabbles ended. Berman took over as ranking Democrat and established a good working relationship with Hastings.

In a burst of activity last May, the two leaders announced a flurry of investigations -- focusing on Rep. Bob Ney, R-Ohio, with links to convicted lobbyist Jack Abramoff, and on the Democrat at the center of a separate bribery probe, Rep. William Jefferson of Louisiana.

Ney agreed in September to plead guilty to two criminal charges in the congressional corruption probe spawned by disgraced lobbyist Jack Abramoff. Jefferson, also the subject of a criminal investigation by the Justice Department, has denied any wrongdoing.