Four staff members for U.S. Rep. William Jefferson, D-La., have been subpoenaed to testify at his upcoming corruption trial, records show.

The summonses issued to the congressman's staffers were revealed when they sent letters to U.S. House Speaker Nancy Pelosi, D-Calif., notifying her they had received the subpoenas, and their letters were published in the Congressional Record, The New Orleans Times-Picayune reported Tuesday.

Authorities say the New Orleans congressman has been indicted on 16 counts, including bribery, racketeering, fraud, money laundering and obstruction of justice, stemming from alleged schemes to procure African deals for local businesses in return for payments to entities controlled by Jefferson's family.

Despite the indictments, Jefferson last week finished first in a Democratic primary election for this House seat, and is proceeding to a run-off election Nov. 4 with the second-place finisher, former TV news anchorwoman Helena Moreno.