THERE has been another bizarre twist in the divorce battle between Frances Bean Cobain and her estranged husband, Isaiah Silva.

The private detective that Courtney Love employed to investigate the death of her husband Kurt Cobain has now been hired by Silva to protect his family from Love and her manager/attack dog, Sam Lutfi, reports the New York Post.

It was reported in July that Lutfi — who notoriously served as Britney Spears’ “manager” during her famous breakdown — had been trying to strongarm Silva, 31, into returning a valuable guitar, which Kurt played in Nirvana’s legendary “MTV Unplugged” session and which is said to be worth millions. Frances, 24, gave it to Silva as a wedding gift.

Sources told the New York Post that Lutfi even threatened Jessica Sullivan, 27, the mother of Silva’s ­seven-year-old child, Arlo, apparently in an attempt to get her to side with Frances in the upcoming divorce proceedings, which will decide the fate of the instrument. Lutfi had telephoned Sullivan, calling her a “w****” and a “c****” and sent her messages saying ominously, “You are done! You sick bitch.”

Now we’re told that Silva has put Tom Grant — who after his investigation into Kurt’s death, concluded that the Nirvana singer was murdered in a conspiracy, and Love is a “psychopath” (although he did not implicate her in Kurt’s killing) — on the payroll.

“The threats only stopped after Isaiah’s family hired Courtney’s former private investigator, Tom Grant,” said a source close to the family. “Tom even stayed overnight at Jessica Sullivan’s home in case Lutfi showed up.”

Grant also posted audio recordings of Lutfi’s calls to Sullivan on the web site BulliesNightmare.com.

Meanwhile, the paper was told that Silva — who, he claims, previously wanted no spousal support from Frances in the divorce — has changed his tune and is now requesting $US25,000 ($33,000) a month, as compensation for the “hell” he’s allegedly suffered at the hands of Love and Lutfi.

This story first appeared in the New York Post.