Inside an ordinary office building six blocks from the Capitol, investigators sift through evidence of possible violations against ethics and laws committed by the nation's elected representatives.

This is the Office of Congressional Ethics, also known as the OCE.

It is one of the most important watchdogs in Washington. That's because the OCE is the only quasi-independent government body whose sole mandate is to formally investigate members of Congress.

But it could soon be silenced by the very people it investigates.

"What is outrageous about it is that you see members of Congress on both sides saying they have zero tolerance for unethical conduct," said Melanie Sloan, a former federal prosecutor who now directs Citizens for Responsibility and Ethics in Washington (CREW).

"But then behind closed doors they are quietly trying to kill the one body in Congress that is seriously going after unethical members."

Sloan's public interest group monitors ethics and legal violations by members of Congress. And, like many other citizen watchdog groups in Washington, CREW is worried that the OCE could soon die through purposeful inaction by Congress.

The ethics office -- which gets its mandate and funding from Congress -- must be reauthorized by this Congress, which soon adjourns, or early on by the new Congress.

What's more, at least four of the OCE's board members are approaching the end of their terms, and new members must be selected and appointed for the organization to continue with its work.

No investigations or reports or real work can be done by the office until their board is in place.

The OCE was formed just four years ago when then-Speaker of the House Nancy Pelosi and others declared they wanted to "drain the swamp" of scandals and corruption in Washington. Among the biggest scandals that prompted action was that of Jack Abramoff, a former lobbyist, who admitted in 2006 to illegally showering gifts on officials in exchange for favors.

The probe into those allegations led to convictions or guilty pleas for 20 lobbyists and public officials -- including a member of the House of Representatives and several aides to congressmen.

Other scandals included those tied to former Reps. Tom DeLay, Mark Foley, William Jefferson and Duke Cunningham.

Since its creation in 2008, the OCE has launched more than 100 investigations of lawmakers, raising serious questions about possible Congressional misdeeds.

In about a third of its investigations, the OCE found that House ethics, and sometimes federal laws, were likely violated. Those 37 cases were referred to the House Ethics Committee for further review.

"The OCE has forced members of Congress to take ethics more seriously," said Sloan. "It has forced the (House) Ethics Committee to act and has let all members of Congress know that they're not going to be able to skate by like they have for so many years, with unethical conduct just going on."

Sloan and her public interest group -- which is considered by some to be a liberal organization -- aren't the only ones worried about the future of the OCE.

Ken Boehm, chairman of the conservative National Legal and Policy Center, agrees that some members of Congress publicly support the office and its efforts to crack down on ethics violations, but are privately trying to kill it.

If the OCE is not reauthorized and new board members are not appointed, Boehm said it would "(send) the message to the public that not only is the ethics system broken, but it doesn't even exist anymore."

House Speaker John Boehner and House Democratic leader Nancy Pelosi would need to lead the effort to reauthorize the OCE and to appoint new members.

Both Boehner and Pelosi say they will do that.

"House Democrats are firmly committed to the continuation of the OCE and replacements will be named at the appropriate time," said Pelosi's spokesman, Drew Hammill.

Similarly, Boehner "intends to retain the OCE for the 113th Congress and to appoint an ethics chair in a timely fashion," his spokesman, Michael Steel, said this month.

But neither Boehner nor Pelosi have made public any more specific actions they have taken. And time for action is quickly running out.

The reauthorization should have really been started before this Congress goes on its winter break to allow for the time that it takes to select and appoint new board members. The new Congress is scheduled to be sworn on January 3.