Britney Spears will not give evidence in parents' defamation trial

Britney Spears's parents are to give evidence at a defamation trial today (Getty Images)

The trial of Britney Spears' parents for defamation of the pop star's ex-manager is due to begin hearing evidence today.

Lawyers for Sam Lutfi declined to say whether he would be the first witness in the case in Los Angeles.

Spears herself will not be giving evidence - she remains under a court-ordered conservatorship and a judge has told her not to participate.

Her father, Jamie, who is her conservator, has been in court with his wife, Lynne, whose book on her daughter's darkest days led to the defamation suit by Mr Lutfi.

He was portrayed by lawyers for the family as a destructive force in Spears' life. His lawyers maintain he was just trying to help her and manage her career.

Mr Lutfi is seeking millions of dollars from Spears and her family.

Spears' father said he was terrified by his daughter's deepening drug addiction as her life spiraled out of control five years ago, his attorney told jurors on Friday.

"Jamie (Spears) was living in constant fear that he was going to look at the TV one day and see Britney was dead," his lawyer Leon Gladstone told jurors.

AP/ Reuters