SACRAMENTO  (AP) — One of the state Senate's top Democrats said Friday that he has been subpoenaed by a federal grand jury, days after another senator's Capitol offices were searched by the FBI.

Sen. Kevin de Leon, D-Los Angeles, said he was served with the subpoena on Thursday, but it was not clear whether the development was related to the FBI raid earlier this week.

"I've communicated to the U.S. Attorney's office my willingness to cooperate fully," de Leon said in a statement. "The U.S. Attorney's office has asked that the details of their inquiry remain confidential. I intend to honor that request."

The subpoena came two days after the FBI raided two Sacramento offices assigned to Sen. Ron Calderon, a Democrat from Montebello. Subpoenas of other lawmakers, aides and lobbyists had been expected as part of the investigation into the business and political dealings of Calderon and his brothers.

De Leon's chief of staff, Dan Reeves, said in response to a question that "we've been advised he is not a target of this investigation."

Neither the FBI nor U.S. Attorney's Office would comment. They also would not say whether more subpoenas are being issued, citing the secrecy of grand jury proceedings.

Rhys Williams, a spokesman for Senate Democrats, said he was unaware of any other senators being served. Spokesmen for Assembly Republicans and Democrats said they also did not know of any subpoenas to lawmakers or staff.

The Associated Press reported Thursday that the FBI began seeking information about Ron Calderon and his brother Tom, a former state assemblyman, as long ago as 2005.