Ex-'American Idol' Contestant Randy Madden Mum on Sex With Minor Allegations

Randy Madden -- the former "American Idol" contestant accused of having sex with a minor -- is refusing to address the allegations ... walking right by photographers who asked him about the charges.

Madden walked out of a Ventura County, California courthouse Thursday ... limping along with a cane in his right hand and holding a phone tightly against his left ear.

Several paps were waiting for Madden -- who appeared on Season 8 of the hit singing competition show -- and they asked him if he had anything to say for himself in regards to his legal predicament.

Madden keeps his eyes down and his thoughts to himself ... jumping in the passenger seat of a waiting car without uttering a word.

ICYMI ... Madden's facing 6 felony charges -- oral copulation of a person under 18, unlawful sexual intercourse, anal and genital penetration by foreign object, sending harmful matter, luring, and dissuading a witness from reporting a crime.

Madden is 45 years old ... we don't know the age of the alleged victim. Ventura County court documents show the charges stem from at least one alleged sexual encounter between July and September of this year. He's pled not guilty to all charges and posted bond ... though he's under strict orders not to contact the alleged victim in the case.