Kim Kardashian and her mother Kris Jenner are suing the reality star's ex-boyfriend Ray J for defamation after he wildly claimed the famous family was under federal investigation.

Kardashian, 44, who was involved in a notorious sex tape with the musician, 44, during their brief romance in 2007, and Jenner, 69, claim in the lawsuit obtained by the Daily Mail that Ray J has 'engaged in a sustained campaign of harassment and defamation' against them for 'more than two decades.'

The lawsuit comes days after Ray J shocked fans by claiming he had been working with the federal government to build a RICO case against Kardashian and Jenner.

During a recent livestream that has since gone viral, he said he is 'gonna say a lot of s***' but did not provide details on what he claims his ex-girlfriend and her family have done.

In the clip circulating on social media, he accused his ex of racketeering conspiracy, saying: 'The federal RICO [Racketeer Influenced and Corrupt Organizations Act] I'm about to drop on Kris and Kim is about to be crazy. I'm talking about, I'm on the news every day. I'm gonna say a lot of s***.'

He also said: 'Anybody that is cool with Kim, they need to tell her now, the feds is coming. There's nothing I can do about it.' 

'It's worse than Diddy,' he later wildly claimed as he compared his unsubstantiated claims to the trial of Sean 'Diddy' Combs, whom he has continued to defend.

The Kardashian-Jenner suit, filed Wednesday, claims Ray J was 'unable to accept the end of his fleeting relationship with Ms Kardashian over twenty years ago... [and] has repeatedly sought to attach himself to Plaintiffs’ names and exploit their prominence for personal gain.'

This action arises from Ray J’s latest and most malicious defamatory conduct: declaring to millions of social media viewers that Plaintiffs are subjects of a federal criminal racketing investigation.

It continued: 'Ray J’s public statements are blatantly false. No such federal investigation exists; no law enforcement agency has initiated any criminal proceedings or investigations related to racketeering charges against Ms. Kardashian or Ms Jenner; and no credible evidence whatsoever supports these inflammatory allegations.

'These statements were presented as factual assertions about ongoing federal criminal proceedings, not as speculation or opinion. 

'Ray J’s publication of these serious criminal accusations without any attempt at verification or corroboration from legitimate law enforcement sources — who would have readily confirmed that no such investigation exists — constitutes reckless disregard for the truth under the actual malice standard. 

'His reliance on his own unsubstantiated assertions, despite having no factual basis or credible source for these inflammatory allegations, demonstrates a fundamental disregard for truth and a willful intent to harm Plaintiffs’ reputations.'

Alex Spiro, lawyer for Kardashian and Jenner, told the Daily Mail: 'Kris Jenner and Kim Kardashian have never brought a defamation claim before nor have they been distracted by noise - but this false and serious allegation left no choice.'

The Daily Mail has contacted representatives for Ray J for comment and has yet to hear back. 

Earlier this year, Ray J also brought up the Kardashians while discussing Combs's sex trafficking case on TMZ's United States V Sean Combs: Inside the Diddy Trial documentary on Tubi.

He questioned the charges against Combs but pointed an accusatory finger at the reality TV family instead. 

'If you told me that the Kardashians were being charged for racketeering, I might believe it,' he said at the time. 

In more controversy, Ray J also brought up his past with Kardashian in an August interview with Cam Newton. 

About the lasting impact of their leaked sex tape, he said: 'That was probably the worst thing that's ever happened to me, if you look from then to now. 

'It's the worst thing that's ever been put on my name,' he continued. 'It's the most disgusting, the most illegal, and the most distasteful when you have a daughter.' 

Ray J and Kardashian were previously in a relationship nearly two decades ago. 

Their romance was confirmed and went public in 2007 when their infamous sex tape was leaked. 

Their relationship had previously began in 2002 when they met amid her divorce from Damon Thomas. 

She has since been married and divorced two more times. She was married to Kris Humphries from 2011 to 2013. 

And her most famous romance was with controversial rapper Kanye West from 2014 to 2022. 

She shares four children — daughters North and Chicago as well as sons Saint and Psalm — with the musician.