Eighteen months into the 110th Congress, federal investigators are still taking a hard look at the 109th, adding to the incredible tally of lawmakers from that body to reportedly be investigated by the FBI for corruption.

Recently revealed investigations of two former lawmakers bring that total to 21. Some of those 21 investigations have closed with no charges, some seem dormant, some are ongoing, and some have resulted in convictions. Since the FBI doesn't comment on ongoing investigations, it's often hard to determine the status. But the total clearly demonstrates that public corruption is one of the FBI's top priorities. The FBI told us the number of agents focusing on public corruption jumped by more than 56 percent in the past several years -- from 451 agents in fiscal 2001 to 705 in fiscal 2008.

Last Friday, the FBI raided a New York lobbying firm as part of an investigation by the Justice Department's Public Integrity Section into ex-Rep. John Sweeney (R-NY). And a former aide to ex-Rep. Ernest Istook (R-OK) pleaded guilty last week to accepting gifts from Jack Abramoff's lobbying firm in exchange for help with Abramoff clients.

Below is a rundown of all 21 lawmakers, current and former. Ten of them are no longer in office. Investigations of seven are part of the Abramoff investigation. Seventeen are Republicans, four are Democrats. This total, based on prosecutorial filings and unambiguous news reports, does not include at least three reported federal investigations of lawmakers for matters other than corruption, including Ex-Rep. Mark Foley (R-FL). All the lawmakers, with the exception of those who have pleaded guilty, deny wrongdoing.

Two of those investigations resulted in convictions:

• Ex-Rep. Duke Cunningham (R-CA) pleaded guilty to accepting bribes from two defense contractors in 2005. He's currently serving a sentence of eight years, four months in prison.

• Ex-Rep. Bob Ney (R-OH) pleaded guilty to accepting bribes from Jack Abramoff and his associates in September of 2006 and was sentenced to 30 months in prison. After serving one year, he was released to a halfway house, which he's likely to leave at the end of the summer.

Two lawmakers have been charged:

• Rep. William Jefferson (D-LA) was indicted last June on bribery charges, but extensive litigation stemming from an FBI raid of his Congressional office has delayed the trial.

• Rep. Rick Renzi (R-AZ) was indicted in February on extortion, wire fraud, money laundering and other charges. He has also yet to go to trial and has said he will not seek reelection.

Four current and former lawmakers appear to still be under investigation related to the Abramoff scandal:

• A grand jury has issued a number of subpoenas regarding ex-Rep. Tom DeLay's (R-TX) and his wife's relationship with Abramoff. Two of his former aides have pleaded guilty to corruption charges, but DeLay has not been charged.

• FBI agents raided the Virginia home of Rep. John Doolittle (R-CA) and his wife in April of 2007 as part of the Abramoff investigation. But he also still hasn't been charged. He's not seeking reelection.

• Ex-Rep. Ernest Istook (R-OK) appeared as "Representative #4" in guilty plea documents of his former aide John Albaugh. The filing describes a 2003 conversation between Istook and Abramoff, during which the lawmaker thanked the lobbyist for providing a skybox at FedEx Field for a fundraiser and then asked what appropriations Abramoff's clients could use. Istook says he's met with investigators and has been told he's not "a target" of the investigation. However, prosecutors typically only issue a "target letter" as a warning that they are moving toward filing charges. Albaugh has agreed to cooperate with prosecutors in exchange for a reduction in sentence. Istook did not seek reelection in 2006, instead making a failed gubernatorial bid.

• In the spring of 2007, FBI agents sought emails and other documents related to Rep. Tom Feeney's (R-FL) participation in a 2003 Scotland trip organized and paid for by Jack Abramoff. Feeney has started a legal defense fund to cover fees related to the investigation.

Eight lawmakers are apparently under investigation for other matters:

• Grand jury subpoenas issued in the Ex-Rep. John Sweeney (R-NY) investigation reportedly focus on earmarks he obtained for clients of a lobbying firm that employed his wife. The New York Timesreports the investigation is also part of the Abramoff investigation, but it's unclear how precisely.

• Ex-Rep. Curt Weldon (R-PA) lost re-election in 2006 after the FBI raided his daughter's home and office, among other locations. The investigation reportedly centers on his advocacy for his daughter’s lobbying clients. A former aide has pleaded guilty to accepting corrupt payments from a Russian non-profit.

• A federal grand jury in Washington has been investigating whether Ex-Rep. Jim Gibbons (R-NV) accepted illegal gifts from a defense contractor.

• Rep. Don Young (R-AK) has spent over $1 million on criminal defense lawyers, but has refused to discuss the nature of the allegations. The Wall Street Journalreported last year that federal investigators were examining whether Young had accepted bribes, illegal gratuities or unreported gifts from VECO Corp., an Alaska energy company.

• The FBI is also investigating whether Sen. Ted Stevens (R-AK) accepted such payments or gifts from Veco. The FBI searched his home last summer.

• Rep. Jerry Lewis (R-CA) has paid more than $1 million in legal fees since June of 2006 in connection with an investigation by the U.S. Attorney’s Office for Los Angeles. The probe reportedly centers on Lewis’ earmarks for clients of his longtime friend, lobbyist Bill Lowery.

• Federal grand jury subpoenas issued in September of 2006 focused on Sen. Robert Menendez's (D-NJ) relationship with a publically funded nonprofit group to whom he'd rented office space. In August 2007 the grand jury shifted focus to the lobbying work of his former chief of staff Kay LiCausi. No charges have been filed. Both Menendez and LiCausi have retained lawyers.

• Rep. Alan Mollohan (D-WV) has been under investigation since May 2006 for earmarks to nonprofits he created. The grand jury subpoenaed at least one witness, in June 2007, to testify about his finances. According to Roll Call, he spent about $80,000 on legal fees in the second half of 2007.

There have been no reported developments in two investigations for 18 months:

• The FBI interviewed a number of Ex-Rep. Katherine Harris' (R-FL) aides as part of investigation into her relationship with defense contractor Mitchell Wade, who's pleaded guilty to bribing Duke Cunningham. There have been no reported developments in the case since late 2006, when she made a failed bid for the Senate.

• Federal agents interviewed officials in Monrovia and Fontana about several of Rep. Gary Miller’s (R-CA) land deals with the California cities. The Los Angeles Timesreported in the summer of 2006 that Miller may have improperly avoided paying millions in capital gains taxes by mischaracterizing the sales as forced by eminent domain. The scope of that investigation, which involved the FBI, was always unclear, and there have been no reported developments since early 2007. Miller has consistently and vigorously denied any wrongdoing.

Three investigations have either been closed or gone dormant:

• Ex-Rep. J.D. Hayworth (R-AZ),who was the second largest congressional recipient of gifts from Jack Abramoff and his associates, says his lawyers were told by investigators in December of 2007 that the investigation of his relationship with Abramoff had been closed.

• Ex-Sen. Conrad Burns (R-MT) was similarly notified around the same time. Both Hayworth and Burns lost reelection in 2006, in large part because of the Abramoff scandal.

• A Justice Department probe in 2005 centered on whether Rep. Jane Harman (D-CA) had sought to aid the American Israel Public Affairs Committee in return for AIPAC's help in persuading House Speaker Nancy Pelosi (D-CA) to appoint Harman chair of the intelligence committee. The probe had found no evidence of wrongdoing and and was considered dormant, the Washington Postreported in late 2006.
  

Matthew Schwarzfeld and Matthew Townsend provided reporting for this story.