Claressa Shields has threatened to sue Jake Paul after his management team claimed the boxing champion and MMA star asked to fight on his undercard.An ongoing war of words between the pair has been raging since October, when Shields said she would "never fight on the undercard of someone who does not possess the skills or accomplishments that I have."Shields also claimed she would "beat him up" if she met Paul in the ring. Paul then savagely taunted Shields after she lost her second MMA fight to Abigail Montes.The feud intensified this week when Shields teased Paul on Twitter for reportedly including a "no knockout clause" in his fight against Tyron Woodley later this month.She tweeted: "It's hilarious to see Jake get asked about the no Knockout clause."Say my name b*tch! You come for me, I come for you. Google 'NDA' It's only a question though."Paul’s management company BAVAFA Sports, headed by Nakisa Bidarian, swiftly responded: "What's hilarious is the multiple times you and your team tried to be a part of a Jake Paul event. Time reveals all. #Receipts."Shields' manager, Mark Taffet, then waded in, posting: "Hey Nakisa @BAVAFASports let the fighters speak for themselves. If you want to engage in debate with me just let me know. I am not Claressa; she's not me. My discussions are my words, not hers."

The 26-year-old Shields shared Taffet’s post with the caption: "Never have I ever. I’m bout sue @jakepaul & his team for defamation and of character cause I ain’t never asked to be on no undercard of no YouTuber!"

She later added: "They bout to have to write a check they ass gonna hate having to cash. Because you talk trash but lying on me is another story! I’m a BIG BOSS WITH A BIG LAWYER!"

Shields is the only boxer in history, female or male, to hold all four major world titles in boxing, simultaneously, in two weight classes.

She is also a double Olympic gold medallist, having triumphed at London 2012 and Rio 2016.

Shields first made a foray into MMA in June, beating Brittney Elkin, but then losing to Montes in October.

She will turn her attention back to boxing next. The American will take on mandatory challenger Ema Kozin in a defence of her WBA, WBC and IBF middleweight titles in January in Cardiff.

Paul first entered the world of boxing in 2018, when he defeated British YouTuber Deji Olatunji in an amateur bout. He then turned professional in January 2020, beating another YouTuber, AnEsonGib.

The 24-year-old has won his remaining three fights, although they have been against a former NBA basketball player and an MMA fighter.

He was scheduled to fight Love Island star Tommy Fury, brother of Tyson Fury, later this month.

Injury forced Fury to pull out of the fight, however, and Paul will fight Woodley for a second time instead.