Britney Spears Former Nanny Refutes Lutfi's Drug Claims

We spoke with Leah Frand -- who worked for Britney for roughly 6 months back in 2007 ... and says she lived at Brit's home and was around the pop star 24/7. Leah tells us point blank, "I have never seen meth in that house or any type of drug."

As we previously reported, Lutfi made claims in court that he found a bag of meth in the house around the time of Britney's meltdown. In fact, Lutfi claimed Britney was so paranoid about getting caught, she shaved her head so officials couldn't test her hair for drugs.

Frand tells us ... Sam was so desperate to stay in Britney's world, he may have planted the drugs in her home ... as part of a diabolical scheme to become her life coach.