Britney Spears' manager Sam Lutfi was unknown to Barry Weiss

A top recording executive testified Monday that he was Britney Spears' "lifeline" during the darkest days of her well-documented meltdown and never heard that she had a new manager named Sam Lutfi, The Associated Press reports.

Barry Weiss, who headed Jive Records, Spears' recording label, said his only contact with Lutfi in 2007-08 was when Weiss asked him for assurance that Spears would be on set to record a music video for her "Blackout" album.

"Britney was pretty erratic at the time," Weiss testified during trial in a defamation lawsuit brought by Lutfi against Spears' parents.

Lutfi says he was Spears' personal manager and deserves millions as his share of her income during that period.

The defamation suit stems from the way Lutfi is depicted in a book written by Spears' mother, Lynne, that detailed the star's meltdown.

Conservators of Spears' estate, including her father, Jamie, who was in court, contend that Lutfi was never her manager but was simply a user who inserted himself into Spears' life and preyed on her vulnerabilities.