LOS ANGELES (CBS) —  A hearing is scheduled next week to determine if Stevie Wonder’s nephew will have to stand trial on charges stemming from an alleged extortion scheme against the singer, a spokeswoman for the District Attorney’s Office said.

Alpha Lorenzo Walker and co-defendant Tamara Eileen Diaz are accused of threatening to reveal information they claimed would be embarrassing to the entertainer if he didn’t meet their demands, according to Jane Robison of the District Attorney’s Office.

Walker and Diaz, both 38, are charged with a felony count of extortion.

The criminal complaint alleges that the crime occurred May 2, the same day Walker and Diaz were arrested by the Los Angeles Police Department’s Robbery-Homicide Division.

The two — who have pleaded not guilty — remained jailed pending their preliminary hearing, which is scheduled for Wednesday at the downtown Criminal Courts Building.

Suraya Fadel, reporting for CBS2 and KCAL9, says Wonder has made no public statements regarding the arrest or allegations against his nephew.

Fadel went to Diaz’ front door. There, her mother told Fadel “does she know Stevie Wonder? No, she doesn’t.” Diaz’s mother also refused to discuss her daughter’s relationship to, or with, Walker. When pressed for answers, all she would say was, “I am in total distress. I can’t say anything. I do not know anything. I do not wanna say anything.”

(©2012 CBS Local Media, a division of CBS Radio Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. Wire services contributed to this report.)