Federal investigators were running wiretaps for months at a time in 2006 on then-U.S. Rep. Curt Weldon's chief of staff and other members of his inner circle, the U.S. Justice Department has revealed.

The wiretaps were disclosed in letters that the department recently sent to individuals - including this reporter, then employed at another newspaper - whose phone conversations with the targeted parties were intercepted.

The notifications, required under federal law, often are sent toward the end of an investigation or when the disclosure would no longer affect an ongoing investigation.

Legal observers say that the wiretap disclosure could be another indication that the corruption probe that helped end Weldon's lengthy political career has concluded.

Weldon, a Delaware County Republican now working for Exton-based Defense Solutions, has not been charged. He has maintained his innocence since the existence of the investigation was leaked three weeks before the November 2006 congressional election. Weldon lost his bid for an 11th term to Democrat Joe Sestak, who now is considering a run for Senate.

Howard Sklamberg, deputy chief of the U.S. Attorney's Office's fraud-and-public-corruption section, declined to comment Tuesday.

The cell phone of Charles Sexton Jr., former Springfield GOP chairman and senior adviser on Weldon's re-election campaign, was tapped in July and August 2006, then again in mid-October 2006.

On Oct. 16, 2006, FBI agents raided the homes and business office of Sexton and Weldon's daughter, Karen. The agents reportedly were investigating whether the congressman had used his position to steer about $1 million in lobbying contracts to their firm.

The feds also were eavesdropping on Weldon's chief of staff, Russ Caso, from March to July 2006. Caso later pleaded guilty to failing to list a conflict of interest in his 2005 congressional disclosure forms, and agreed to cooperate against Weldon. He is scheduled to be sentenced later this month.

The telephone of Cecelia Grimes, a lobbyist and close friend of Weldon's who was sentenced last month for destroying evidence - she threw her BlackBerry into an Arby's garbage can and tried to ditch other Weldon-related records - also was tapped in spring 2006.

Jules Epstein, an associate professor at Widener University School of Law, said that the disclosure of the wiretaps and sentencing of cooperating witnesses appears to indicate that the probe is winding down, possibly without additional indictments.

Attorneys for Grimes, Sexton, Caso, and Curt and Karen Weldon either declined to comment or did not return messages on Tuesday. It is unclear whether the congressman's phone ever was tapped.