Kanye West has launched a furious tirade at Taylor Swift, calling her a liar for claiming she knew nothing about lyrics in his new single in which he calls her a "b*tch" and raps about having sex with her.
In an astonishing 15 tweet outburst, Kanye begins by saying he "did not diss" the 26-year-old singer and he has "never dissed her".
But he then launches into a rant about how he called her on the phone, had an hour-long conversation with her about the song Famous, she found it "funny" and she gave him her blessing.
Furthermore, he defends use of the word "b*tch" in the song, saying it is an "endearing term" in hip hop, like the word "N*gga".
In the track Famous, which also features Taylor's enemy Rihanna, Kanye raps: "I feel like me and Taylor might still have sex.
"I made that b*tch famous."
In what could be seen as a jump in logic, Kanye even claims that the line "I made that b*tch famous", was actually her idea.
In the tweets he writes: "I'm not even gone take credit for the idea... it's actually something Taylor came up with.
"She was having dinner with one of our friends who's name I will keep out of this and she told him... I can't be mad at Kanye because he made me famous! #FACTS.
"Stop trying to demonize real artist. Stop trying to compromise art."
Kanye's outburst then descends into a lament about the way the music industry is going, saying "music is so f***ing watered down right now."
"I miss that DMX feeling. I miss that feeling so that's what I want to help restore.
"They wan to control us with money and perception and mute the culture."
He then appeared to calm down with a tweet more than an hour later, in which he said he wanted to be "creative director of Hermes".
He subsequently released a picture of the updated set list for his new album, as well as linking to one of the new tracks, 30 Hours, on Soundcloud.
Kanye's latest rant is certain to pour gasoline on a feud that stems back to the 2009 MTV Video Music Awards when he infamously stormed the stage while Taylor was accepting an award.
During the incident, dubbed "Imma let you finish", he demanded that Beyonce receive the award for Best Female Video while a visibly shocked Taylor looked on.
The pair had been thought to reconcile, and were apparently on good terms, going to dinner, sending flowers and even chatting on the phone, but that appears to have now changed.
Following the release of the controversial track yesterday, Taylor's spokesman claimed that Kanye had called the 1989 singer to ask her if she would release his single Famous, on her own Twitter account, a request she denied.
She denied a report that she gave Kanye her blessing to rap about having sex with her in the track.
Taylor was stunned to learn of the way she was referenced in the song, which was debuted at his new album listening party and fashion show in New York City on Thursday night.
Her spokesman said in a statement to MailOnline: "Kanye did not call for approval, but to ask Taylor to release his single Famous on her Twitter account.
"She declined and cautioned him about releasing a song with such a strong misogynistic message.
"Taylor was never made aware of the actual lyric, 'I made that b*tch famous'."
The pop star's strong reply denies a report by TMZ.com claiming Kanye, 38, called Taylor last month to tell her about the lyric and explain it was a joke.
Kanye has come under fire from Taylor's friends Gigi Hadid and Jaime King, as well as the singer's angry brother Austin Swift who shared a video of himself throwing away his Yeezy shoes in response.
The new track was played at Kanye's New York Fashion Week Yeezy Season 3 show and listening party for his new album The Life Of Pablo at Madison Square Garden on Thursday.
Model Hadid, 20, took to Twitter after being spotted at the Yeezy Season 3 fashion show and listening party at Madison Square Garden in New York City.
"My attendance somewhere does not mean I agree with everything being said in the music playing there. My friends know of my loyalty," Hadid tweeted to her more than 1.5 million followers on Twitter.
Gigi and Taylor have been close friends for some time and the top model appeared in the pop star's Bad Blood video.
Austin, 23, took to Instagram, posting a video of himself throwing his $950 Moonrock Yeezy Boost 350 trainers in the bin with the caption, "Getting a head start on some spring cleaning. Here we go again."
The video shows Austin carrying a trash can while whistling the Colonel Bogey March.
He places the trash receptacle down and then pulls a pair of Moonrock Yeezy Boost 350 off a shelf and tosses them into the bin.
Jaime King also took to Twitter to stand by Taylor, who is godmother to her baby son Leo Thames.
She wrote: "I'm so sad right now & disappointed right now. I stand by my sister. Always."
Jaime, who attended the launch at Madison Square Garden, had initially shared a picture of the show on Instagram, but deleted it in the wake of Kanye's song.
After Kanye's rant on Friday morning, Jaime retorted with an Instagram picture of her and Taylor, with the caption "hand in hand".
Ruby Rose, who spent New Year with Taylor and her boyfriend Calvin Harris in Las Vegas, said Kanye had gone too far, not only for the lyrics but his recent outbursts about Bill Cosby and Amber Rose.
"Too many lines crossed," she wrote. "If I put myself in the shoes of the women he has hurt recently. Victims of Bill Cosby, The Slut shaming, Amber... And now my dear friend Taylor.. Right before another huge moment for her... Can I still support him and call myself a feminist? A friend? No."
Taylor's best friend, supermodel Karlie Kloss, who is an adidas ambassador, was also in attendance at the show and posted a photo on Instagram of herself proudly gazing at her Yeezy trainers. She has yet to comment on the uproar, although she has been active on social media.
"Taylor wasn't the only celebrity that Kanye referenced. He also mentioned his brother-in-law Rob Kardashian's new girlfriend Blac Chyna, and how she has been helping him 'sexercise'.
"Blac Chyna f***in' Rob, help them with the weight / I wish my trainer would tell me what I overate," he rapped.
Even his 'b*tch' wife Kim Kardashian's bedroom antics got a mention - although not with him.
The 35-year-old's infamous first step on her way to super-stardom was a sex tape with former boyfriend Ray J, who in 2013 famously laid down the not-very-subtle diss track I Hit It First.
And on Thursday, Kanye responded in kind: "I bet me and Ray J would be friends / If we ain't love the same b*tch / Yeah, he might have hit it first / Only problem is I'm rich."
In his Twitter outburst, Kanye says he asked for his wife's blessing to mention her, and she was "cool with it".