Ending months of speculation, the House ethics committee announced Wednesday that it has begun an official investigation into allegations that unnamed GOP lawmakers improperly pressured Rep. Nick Smith (R-Mich.) to back a Medicare prescription drug bill during a controversial Nov. 22 vote.

The Committee on Standards of Official Conduct voted Wednesday to establish an investigative subcommittee to “conduct a formal inquiry regarding certain allegations related to voting on the Medicare Prescription Drug Improvement and Modernization Act of 2003,” the panel said in a statement released Wednesday. The full ethics panel had met behind closed doors earlier in the day to approve the step, the first time in two years that an investigative subcommittee has been authorized.

The statement added: “The investigative subcommittee will have jurisdiction to conduct a full and complete inquiry into alleged communications received by Representative Nick Smith linking support for the congressional candidacy of his son with Representative Smith’s vote on that legislation.”

The investigative subcommittee will issue a report to the full panel at the end of its inquiry, a document that does not have to be released publicly unless the committee votes to take further action.

Rep. Joel Hefley (R-Colo.) and Alan Mollohan (D-W.Va.), chairman and ranking member of the ethics committee, plan to choose the four Members for the investigative subcommittee “very soon,” but had not done so as of last night, according to informed sources.

There are several options that Hefley and Mollohan could exercise to determine the makeup of the investigative subcommittee. All four lawmakers on the smaller panel, including the chairman and ranking member, could come from the full ethics committee, or Hefley and Mollohan could draw on a new pool of Democratic and Republican lawmakers nominated by Speaker Dennis Hastert (R-Ill.) and House Minority Leader Nancy Pelosi (D-Calif.) for two of the participants.

At press time, Hastert had not yet released his picks for the “ethics pool.” Pelosi has selected Reps. Xavier Becerra (D-Calif.), Bill Delahunt (D-Mass.), Adam Schiff (D-Calif.), Bobby Scott (D-Va.) and Bart Stupak (D-Mich.).

Smith himself has declined to say anything further about the substance of the matter, although he did acknowledge that a formal probe of the incident had begun.

“My office has been advised that the House Committee on Standards of Official Conduct has elected to establish an investigative subcommittee to examine circumstances surrounding the November 21-22, 2003, prescription drug/Medicare vote in the House,” said Smith in a statement, adding that he would “cooperate fully with the inquiry.”

House Democrats, led by Minority Whip Steny Hoyer (D-Md.), have insisted for months that the ethics committee begin a formal inquiry into the Smith case, and threatened to end a seven-year ethics truce between the two parties unless they got their way.

“I was pleased to learn that the Committee on Standards of Official Conduct voted earlier today to initiate an Investigative Subcommittee on the allegations raised and repeated by Congressman Nick Smith related to the Medicare Prescription Drug vote last year,” Hoyer said in a statement. “I believe that this is an appropriate and necessary action and the only way that the House can remove the cloud of suspicion that hangs over this matter to this day.”

Pelosi echoed Hoyer’s view. “These are serious allegations, and this is an appropriate step for the committee to take,” said Brendan Daly, Pelosi’s spokesman.

Hastert’s office did not return several calls seeking comment.

Ethics watchdog groups were also pleased that the ethics committee moved toward a formal probe of the Smith matter, although they still believe that outside groups should be allowed to file ethics complaints on their own against Members, as is allowed by the Senate.

“We’re happy that the committee has decided to do the right thing,” said Mark Glaze, spokesman for the Campaign Legal Center, which first filed complaints about the Smith allegations with the Justice Department. “Still, we need to stay focused on the fact that had there been a formal mechanism allowing outside groups to bring complaints this investigation would have gotten under way three months ago when memories were still fresh.”

Gary Ruskin, director of the Congressional Accountability Project, said “it is good that they are launching an investigative subcommittee, but it is something they should have done three months ago.”

“It isn’t rocket science that this is something that needs investigating quickly,” he said. Ruskin added that committee’s investigation should not be allowed to interfere with any ongoing Justice Department probe. “If the Justice Department is looking at this, the ethics committee should step aside,” he said. The FBI has begun its own investigation into the Smith case, although it’s unclear what will happen to that probe now that the ethics committee has taken it up.

Hefley and Mollohan announced on Feb. 3 that an informal fact finding had been initiated by the ethics committee on its own authority less than three weeks after the Medicare vote, an announcement that contradicted an Jan. 21 statement by Hefley that the ethics panel would probably not look into the matter unless there were a formal complaint from a Member.

In the days following the Nov. 22 vote, Smith claimed he was offered $100,000 in campaign contributions for his son, Bradley Smith, who is seeking to succeed him in the House. Smith has softened his position somewhat since then, although he continues to insist that he was offered “significant financial support” for Bradley Smith if he switched his vote.

Hastert left open the Medicare vote for nearly three hours as top Republicans and White House officials tried frantically to convince GOP lawmakers to support the $400 billion Medicare prescription drug package, a major legislative initiative for President Bush and the party leadership.

The day after the vote, Smith, who opposed the bill despite extensive lobbying from party leaders, charged that unnamed senior Republicans used “bribes and special deals” to convince wayward GOP lawmakers to support the proposal. The Medicare bill passed by a 220-215 vote.

Just over a week later, Smith told a Michigan radio station that he was offered $100,000 for Brad Smith’s campaign if he voted “yes,” and syndicated columnist Robert Novak reported that Smith was taunted by other Members, including Rep. Duke Cunningham (R-Calif.), after casting his no vote. These Members allegedly told Smith that his son would never make it to Congress because of his vote on the Medicare bill.

Erin P. Billings and Damon Chappie contributed to this report.