Britney Spears' mother Lynne has slammed the pop star's former 'manager' Sam Lufti for taking advantage of the singer's naivety and targeting her like a "predator."

The star suffered a mental and emotional breakdown at the start of the year after losing custody of her two sons by ex-husband Kevin Federline in late 2007.

Lutfi was a constant presence at the singer's side until he was served with a restraining order in February and ordered to stay away from Spears and her family. The legal ruling came amid accusations by Lynne that he had drugged the star.

In her forthcoming book, "Through The Storm - A Real Story of Fame and Family in a Tabloid World," Lynne describes how Lutfi worked his way into her daughter's life and tried to cut her off from her loved ones.

She writes, "She (Britney) was sad, floundering, ripe for a predator to come along. Britney was open to this man who rode in on a white horse. Within a month of meeting, Sam was in complete control of her life. He appointed himself as her gate-keeper, and there was no one he wanted to keep the gate closed to more than Britney's family."

Lynne goes on to tell how Lutfi claimed Britney would commit suicide if they tried to sack him, threatening, "If you try to get rid of me, she'll be dead and I'll p**s on her grave."

Britney was put under her father Jamie's conservatorship after her personal troubles, and has since regained her health and access to her sons Sean Preston and Jayden James.

Lutfi's restraining order came to an end this summer after Jamie Spears decided against applying for an extension of the ban.

(This news article provided by World Entertainment News Network)