Britney Spears' former manager Sam Lutfi is also a defendant in the lawsuit around a claimed attempt to regain possession of Kurt Cobain's iconic 'Unplugged' guitar.

Courtney Love is being sued by her daughter's ex-husband, alleging she conspired to have him murdered over ownership of her late husband Kurt Cobain's 1959 Martin D-18E guitar that was used during Nirvana's iconic MTV Unplugged in New York performance in 1993.

Along with several others, Sam Lutfi -- who managed Britney Spears during her public meltdown in 2007 -- is also named in the suit and accused of supplying illicit drugs to Love's daughter, Frances Bean Cobain, as well as kidnapping, attempted murder, false imprisonment, extortion and more. Actor Ross Butler, star of 13 Reasons Why, is also accused of playing a role.

According to the civil complaint filed in Los Angeles County, Love, Lutfi and Butler entered into a criminal conspiracy to commit trespass, burglary, home invasion, robbery, assault, battery, kidnapping and murder against musician Isaiah Silva, all in order to take possession of the guitar, which is believed to be worth millions of dollars. Billboard has reached out to Love's rep for comment.

A source close to the family told Billboard, "Frances and the family are prepared to fight with a fury of unprecedented legal force and they will prevail."

Since Cobain filed for divorce from Silva in 2016, the guitar has been the subject of public interest and a point of contention in the couple's settlement. (The rare acoustic-electric 1959 Martin D-18E was produced for just a year before being discontinued and the left-handed Kurt Cobain had its bridge and nut adapted so he could play it upside down.) As the press has followed the matter over the past couple years, Love has spoken out on the subject, calling it a "treasured heirloom of the family" and saying, "It's not [Silva's] to take."

But, according to the suit, the guitar was gifted to Silva by Cobain in 2014 six months before their wedding as a dating anniversary present, marking a sentimental time in their turbulent relationship. The documents go into great depth detailing Sivla's gift to Cobain for the same anniversary -- an extravagant and heartfelt conversion of the couple's spare bedroom designed, essentially, in tribute to Cobain and her interests. The lawsuit also notes that Cobain needed Love's permission to remove the Martin D-18E guitar from storage, as both of their consent was required for such a decision.

As well, it is described that Cobain never showed any interest in or asked that Silva return the guitar when she initially left him in February 2016 and filed for divorce a month later. Yet, according to Silva's suit, once Love and her business manager and so-called "rottweiler" Lutfi got involved, the battle over the guitar -- along with some property rights -- became life-threatening.

Silva and Cobain began dating in 2010 and started living together a year later. But, according to Silva's lawsuit, when Love moved to Los Angeles to be closer to her daughter in 2012, soon after Lutfi began supplying Cobain with narcotics and illicit benzodiazepines, which Cobain and Lutfi referred to as "cookies." Often the drugs would be delivered by Butler in secret, without Silva knowing.

From there, according to Silva, Cobain developed an addiction, which was supported by Lutfi, causing great strain to their relationship and resulting in Silva ending their engagement at one point. In 2014 the couple married, but Cobain's alleged drug use only intensified over the years, leading up to a grand mal seizure later that year that nearly killed Cobain at the couple's home while Silva was there with his young daughter, Arlo. Still, according to the suit, her drug use persisted leading up February 2016 when she disappeared from the couple's home in West Hollywood, California.

As Silva and Cobain worked to amicably settle their divorce without attorneys, the lawsuit says the guitar became a point of contention for Love and Lutfi and the two "became obsessed with finding a way to retrieve the guitar from Silva."

From there, Love, Lutfi, Butler and a chauffeur named Yan Yukhtman allegedly hacked into Silva's iMessage account and sent out messages "making it appear Silva was despondent and on a mental precipice contemplating suicide." This was allegedly part of a plan to commit a home invasion, kidnap Silva, murder him, make it appear to be a suicide and recover the guitar, as well as remove him from claims to the couple's house, another house they had acquired for Silva's daughter Arlo and her mother and any spousal support.

Silva reported the suspicious activity to the Los Angeles Police Department, noting, according to the suit, that it follows "a disturbingly similar pattern and course of conduct to the modus operandi of Lutfi" in various previous harassment cases. From there, things worsens, as Lutfi and Love allegedly began threatening Silva's friends, family and bandmates in attempt to turn them against Silva.

Shortly after midnight on June 3, 2016, according to the lawsuit, Lutfi, Butler and Yukhtman broke into Silva's house and tried to enter his bedroom -- where he had been watching a movie with a friend -- claiming they were the police. Lutfi allegedly yelled at and threatened the friend, telling him to leave, before Butler and Yukhtman pushed him out of the house. Following some struggling, the documents continue, Silvia was overpowered and then threatened to calm down by Lutfi "grabbing Silva's genitals through his pants, and whispered to Silva, 'Listen f----t, calm the fuck down or we'll drag you upstairs and take turns fucking you.' In fear for his life, Silva tried to appear calm and cooperative. However, he claims, Lutfi, Butler and Yukhtman continued to threaten him and physically removed Silva from his Curson Avenue residence against his will," forcing him into the back seat of a Cadillac Escalade outside and driving off.

Silva's friend had been outside calling 9-1-1 from his car and was able to drive ahead of the Escalade, blocking its way on the narrow canyon road trying to prevent Silva's captors from getting away, the suit claims. When police arrived in cars and a helicopter overhead, Silva claims Lutfi "hurriedly concocted a false story intended to prevent LAPD from arresting them" and threatened the lives of Silva's family -- including his 7-year-old daughter Arlo -- if he didn't go along with it. "In shock and fearing for his life and the lives of his family and daughter," Silva agreed to go along with Lutfi's story that they were old college friends and the kidnapping had been a prank.

Were it not for the intervention of Silva's friend and the LAPD, the suit says, "it is believed, based upon facts and evidence, that Silva would have been taken to a secondary crime scene and murdered on June 3, 2016."

The lawsuit also several times tries to draw parallels between the allegedly false narrative Love and her cohorts attempted to establish around Silva with the often-speculated upon death of Kurt Cobain. Silva claims that Kurt Cobain's mother Wendy O'Connor confided in him that she was "keenly aware of the disturbing correlations between his circumstances and those of O'Connor's late son." She also said that she "believed Love to be involved in the alleged suicide of her son, Kurt Cobain."

Once LAPD left the scene, the suit claims Lutfi, Butler, Yukhtman and Silva returned to the house, where Silva was held hostage for several hours while he was threatened repeatedly over the location of the 1959 Martin D-18E guitar. Silva eventually told Lutfi that the guitar was not there because he was in the process of recording with his band. Eventually, Lutfi allegedly changed his tactic to extorting Silva into signing a settlement agreement looking to accomplish the original objectives of their conspiracy with the help of attorney Marc Gans -- demanding Silva agree to surrender the guitar, any claim to the houses and spousal support from Cobain, as well as all photographs and recordings of Cobain he had acquired during their relationship and marriage. In return, Lutfi said he had convinced Love and Cobain to offer him $120,000 if Silva signed the agreement with those terms and the harassment would end. Eventually, Lutfi left the house, where Silva remained to scared to leave on his own.

Later that day, Silva's mother and sister brought him and his daughter Arlo back to their home in Orange County for safety. But Lutfi's harassment and threats continued, according to the suit, as he tried to further pressure Silva into signing the settlement agreement, including stalking him and his family. As well, Lutfi allegedly sought to defame Silva and undermine his claims to the guitar and property. According to the lawsuit, Lutfi caused one of Silva's friends to lose his job at the Chateau Marmot, posted a Craigslist ad with his daughter's puppy advertising a free dog with her mother's phone number attached, and illegally rerouted Silva's mail delivery to his own apartment.

Throughout it all, Silva claims he was afraid to go to the police because of the constant threats and he was convinced by Lutfi that he, Love and Cobain "controlled the LAPD, judicial system, and media." Finally on June 8, 2016, he did file a police report and obtained a temporary restraining order against Lutfi later that month.

Silva and Cobain's divorce was finalized last year and the two reached a settlement agreement earlier this year. Silva's attorney Douglass Unger could not speak to whether the harassment ended entirely following the restraining order, but confirmed that under the settlement agreement Silva retained possession of the guitar, while Cobain won rights to the couple's property and was free from any spousal support.