She’s one of the world’s top supermodels, gracing the pages of countless magazines and strutting down catwalks for fashion’s greatest designers, from Paris to Milan and Manhattan. But NAOMI CAMPBELL harbored a dark secret, and now she’s revealing candid details about her tempestuous life on and off the runway in an exclusive “Primetime Live” interview with DIANE SAWYER.

In the one-on-one, airing tonight (Thursday) at 10 p.m. on ABC, Diane asks Naomi about her battle with drug addiction that almost destroyed her: “Did you ever say, ‘I am an addict?'”

“I did,” replies Naomi. “When I was on my knees. When I collapsed on a job … And I said, ‘What more does it take for you to now see you’re on your knees?'”

“Did you ever think of taking your own life?” asks Diane.

“I was very, very low to the bottom of the barrel; I was,” Naomi continues, “and because of that drug. I think that’s a cry for help. I am a fighter in respect; I don’t want the easy way out.”

In addition to describing how she regained control of her life from the drug in question, cocaine, the British-born Naomi also addresses the persistent rumors and tabloid tales of a sometimes violent temper that has allegedly led her to lash out at others.

In 1998, she was sued by her personal assistant, GEORGINA GALANIS, who claimed the model hit her on the head with a mobile phone and threatened to throw her from her car during an argument. Another assistant, SIMONE CRAIG, accused Naomi of striking her, throwing her on a sofa and hurling a phone at her while holding her hostage in a hotel. Other accusations have also been made against Naomi, including a fight with her maid, and the supermodel has reportedly taken anger management classes mandated by the court.