The Washington and New Orleans homes and the vehicle of U.S. Rep. William Jefferson (search) were raided by federal agents on Wednesday.
Bryan Sierra, a Department of Justice (search) spokesman, would not comment on what federal agents were looking for.
"There were searches executed today in connection with an ongoing criminal investigation," Sierra said. "As it is a criminal investigation we will not be able to comment any further."
In a statement from Jefferson, the congressman said he did "not know the extent or precise nature of this investigation."
Jefferson, D-La., added: "I am cooperating fully with the authorities."
Jefferson's statement did not say whether he was in New Orleans or Washington.
Although neither Jefferson nor Sierra gave the point of the raid, Jefferson's brother-in-law, a former state judge, recently was convicted of mail fraud in a wide-ranging investigation of bail bond corruption in suburban New Orleans.
The brother-in-law, Alan Green, was the 14th defendant convicted in the investigation called "Operation Wrinkled Robe." The others, including a former judge, Ronald Bodenheimer (search), pleaded guilty.
According to federal court documents, in a recorded conversation, Jefferson asked Green to raise money for Jefferson's daughter's successful 2003 campaign for the state Legislature. The records show that Green agreed to help.
Previously, Jefferson said that he recalled the conversaton with Green, but the request for help was familial — and not political in nature.
"To my knowledge, nothing resulted from the conversation — the campaign did not receive any money from Judge Green or anyone who may have been prompted by him to contribute — and there were no further conversations on the matter," Jefferson said.
State Rep. Jalila Jefferson-Bullock, D-New Orleans, said in May that she had no knowledge of the matter and did not receive contributions from Green or anyone he might have asked to support her.