CARBONDALE, Ill. -- Police at Southern Illinois University here are investigating a series of fraudulent bills sent to students' parents over the past week, officials said Thursday.

About a dozen fake bills purporting to be from the university were sent to parents of SIUC students across Illinois from Naperville to Champaign to Nashville, and one was sent to SIU parents in Nebraska, said Lt. Kay Doan, who heads the investigation for the university police department.

She did not know whether any of those who received the fake bills sent money.

The letters purport to be statements from a fictitious "FMM Service Department" of the 22,000-student university and demand payment of $86 for student participation in a job-search program, Doan said.

Checks were to be made out to FMM Service Department and sent to a Carbondale post office box. The U.S. Post Office would not immediately say who rented the post office box.

According to the letter, if the money is not sent by Nov. 14, the student will be disqualified from the "student-for-hire 2003 job search program," the letter states.

There is no FMM Service Department or student-for-hire 2003 job search program at the university, said SIU spokeswoman Susan Davis.

Davis said the name signed at the bottom of the letter, Neal T. O'Fallon, is not known at the university. The fake bill is not printed on anything that appears to be SIU letterhead, Lt. Doan said.

"Most statements that come from the university come from the bursar's office, and are on letterhead," Doan said. Anyone who has questions about whether some SIU correspondence is genuine should call the campus police department, she added.

"We want to get the word out to parents and students that if they do receive this letter, they should not send money," she said.