During the ongoing battle with the singer's former employee, Osama 'Sam' Lufti, Lynne Spears has told a US court that he admitted to her that he did so five years ago to help her sleep.
This was thought to have been going on during Britney's public meltdown which saw her shaving her head, temporarily losing custody of her kids and being hospitalised.
Lufti is suing Britney for a share of her fortune, claiming he had an agreement as her manager for 15% of her earnings before he was let go in 2008.
He is also suing over 'lies' about him in her 2008 book Through the Storm, and Britney's father Jamie for allegedly punching him.
However, Lufti has always maintained he was trying to get Britney clean of drugs.
It's thought Lynne Spears told the court he cut off Britney's phone, but despite her worry, didn't call the police: "I was very worried and I didn't know what to do so I tried to get her away from there."
But, admitting that she was estranged from her daughter for a while in 2007, she said how Lufti told her he wanted to help reunite them.
Meanwhile, Lufti, who claims the drug crystal meth was found in Britney's home, has also been accused of planting the drugs as a 'manipulation tactic' by Britney's ex-nanny Leah Frand.
TMZ has reported that Leah, who worked for Britney closely for around six months in 2007, said: "I have never seen meth in that house or any type of drug."
Lufti has also claimed that the 'Toxic' singer 'was so paranoid' she shaved her head so officials couldn't test her hair for drugs.