Adnan Ghalib, Sam Lutfi Fighting Over Britney Spears

Britney Spears' "manager," Sam Lutfi, sent a series of angry text messages to her boyfriend Adnan Ghalib, warning the celebrity news photographer he was "killing her" and setting off Sunday night's massive blowup.

The spat erupted after a hysterical Britney Spears was pictured sitting barefoot outside her L.A. home, sobbing on the pavement.

Adnan Ghalib received text messages from Sam Lufti which read:

• "You're a manic trigger. If you continue to have any contact with her, you'll kill her."
• "It's your decision. You need to cease all contact with her completely."
• "I've tried to work with you helping her but you didn't do as asked only way to help now is disappear. She's never been this way before."

The drama came when Britney reportedly fought with Lutfi over her tryst with Adnan Ghalib, prompting the singer to call Ghalib for help.

Ghalib arrived, but was denied entry to the premises as uber-shady Osama Lutfi warned security not to let him in - and turned Britney's many mobile phones off to ensure he could not reach her, according to the Daily Mail.

The feud between Adnan Ghalib and Sam Lutfi has been raging for weeks.

"They hate each other," says a source, adding that: "Sam doesn't think Adnan is good enough for Britney and Adnan hates the control Sam somehow has on her. Britney is just caught in the middle."

Sam Lutfi reportedly initiated the argument over Adnan Ghalib, warning Britney Spears that her photographer boyfriend is a bad influence.

Talk about the pot calling the kettle brown.

Britney later left with another paparazzo (we think Filipi Teixeira) before meeting up with Ghalib as her father, Jamie Spears, and police arrived.

Many media observers believe that the pair's differences also center on which celebrity photo agency Britney chooses to align herself with.

Ghalib works for Finalpixx. Lutfi is rumored to have a deal in place with X17 in which they take Britney Spears photos and he gets a cut.