The celebrity manager - who is currently giving evidence in his defamation and breach of contract lawsuit against the popstar and her parents Jamie and Lynne - claims that Jamie beat him up after threatening to hurt him so badly he would need to be hospitalised.
According to gossip website TMZ, Sam told the Los Angeles court on Wednesday (24.10.12) that Jamie initially issued the violent threat via text message.
The message reportedly read: ''If and when I met u one thing is going to happen I am going to jail and u r going to the hospital (sic).''
The judge has not yet decided whether or not the jury will be allowed to see the actual message but Sam told the court that Jamie later punched him in the solar plexus and threatened to kill him.
He claims he fled and was forced to lock himself in a game room to protect himself from Jamie.
Last week the 'X Factor' judge's father revealed he was ''scared to death'' at the time of her psychiatric episode in 2008 and thought she would never recover.
The court battle kicked off last Thursday (18.10.12) and saw Sam make a series of damning allegations about drugs, while her legal conservator Jamie claimed Sam's toxic influence was to blame for her breakdown.
The scorned manager alleges Britney's addiction led to her to shave off her own hair in order to destroy evidence of her drug binges when she feared she might lose custody of her children, Sean, now seven, and six-year-old Jayden James.
Britney's lawyer Joel Boxer argued Sam was never legally her manager and has no grounds to sue for 15 percent of her earnings during that period despite his claims that they verbally agreed he would represent her for four years.
Sam is also suing Lynne Spears for comments she made about him in her 2008 memoir 'Through The Storm'.
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