Heath LedgerA former friend of Heath Ledger has claimed his use of prescription and non-prescription drugs spun out of control because he worried he’d lose access to his daughter Matilda.

Rebecca White got to know the actor when she worked as Naomi Campbell’s assistant several years ago and earlier in the week discussed how the Brokeback Mountain star frequently took cocaine with the supermodel. Now Rebecca has claimed that Heath’s drug use prompted his split from Michelle Williams last year and he worried Michelle would use it against him in a custody battle over their two year old daughter.

After their split in September last year, Heath and Michelle had shared custody of the little girl but Rebecca told the Mail on Sunday: “Heath believed Michelle was going for sole custody.”

“She wanted nothing to do with him and many of his friends believed that in the last couple of weeks that really pushed him over the edge. He was getting more reckless than ever with cocaine and heroin.”

“His use of downers - sleeping pills and anti-anxiety pills and antidepressants - was also getting heavier because he needed them to sleep.”

“Heath was a very shy, insecure man. But in celebrity circles you need something to ground you, and for him that was being a father and the idea that Michelle might still take him back and they might still be a family.”

“Even though he was seeing other women, there was one side of him that still wanted their relationship to work. But there was also the side that depended on drugs because he felt like a fish out of the water.”

“He was not the type to have killed himself. The way I hear it, he went out the night before, he was doing cocaine, he wasn’t able to sleep, and the investigators think he woke up, didn’t remember taking sleeping pills and then took what accidentally was an overdose.”

Rebecca added that she thought Heath and Michelle were a “mismatch”: “It was this movie-set romance and Michelle got unexpectedly pregnant. It absolutely would not have lasted if she hadn’t.”

“Heath was an Adonis and she was dowdy and not in his league - careerwise or looks-wise - and no one could understand why they got together.”

“He was a partygoer and Michelle was quite straight. But when she got pregnant, Michelle was determined to have the baby. Heath wanted to do the right thing and stick by her.”

“Michelle kicked Heath out because he would be showing up all hours of the night with this band of hangers-on and doing drugs.”

“Michelle started to talk about going for sole custody. She wanted to be responsible 100 per cent. She felt he couldn’t be responsible for the baby because he wasn’t responsible for himself.”

“He got deeper and deeper into drugs as his fears of losing Matilda increased.”

Heath was found dead in his SoHo, New York apartment on Tuesday afternoon. An initial autopsy proved inconclusive and the city’s Medical Examiner is awaiting the results of further tests before announcing a suspected cause of death.