For the past two months, Kanye West has dominated headlines for a nonstop stream of reprehensible behavior. What started out as a controversy over the rapper’s ‘White Lives Matter’ T-shirts descended into a torrent of antisemitic remarks before he appeared on Alex Jones’ show in early December to praise Nazis and Hitler. “I see good things about Hitler,” West said during the bizarre three-hour interview where he falsely claimed Hitler had invented highways and microphones.

West’s remarks mirrored earlier claims former business and music industry sources had told CNN and NBC this fall — that the musician had lauded Hitler and made several antisemitic comments within the past five years, paying at least two settlements to former employees who allege he made such remarks in the workplace.

But as nearly half a dozen sources who worked with West tell Rolling Stone, his alleged obsession of Hitler and Nazis dates back even further than previously reported. They claim that West has been discussing his admiration for Hitler and what he sees as positive achievements of Nazi Germany for nearly two decades, describing it as a well-known but well-kept secret within the rapper’s inner circle.

Beyond just fascination, two sources claim, West allegedly took inspiration from Nazi propaganda strategies and power-gaining tactics to achieve his own fame and success. “It’s not a stretch to now compare Kanye’s ‘by any means necessary’ methods and tactics with Adolf Hitler’s,” a former longtime collaborator says. “To know that a Hitler/[Joseph] Goebbels playbook has been a central inspiration to Kanye’s own media playbook helps bring a great deal of clarity to the exact types of moves he’s been making over his career.” (West did not reply to Rolling Stone‘s request for comment.)

In the years before the release of West’s 2004 Grammy-winning debut album The College Dropout, West’s success as a rapper was unclear. While he was a wonderkid producer, music label executives believed West’s semi-preppy look and suburban upbringing wasn’t a fit for the gangster rapper image of the early 2000s. West’s persistence won out when he was signed to Roc-A-Fella in 2002 and quickly began working on his first album. It was in those early studio sessions the then-26-year-old frequently discussed Hitler and Nazis and quizzed others on their thoughts, according to a 2003 music industry source who claims to have witnessed the conversations firsthand. “It was like a daily thing,” the source says.

The topic wasn’t couched in general conversation, the music source says. Instead, West allegedly would approach collaborators and industry executives and ambush them with questions — seemingly trying to catch people off-guard. “Going up to somebody like, ‘So what do you think about the Holocaust?’ the music source explains.

Until West received an answer he was satisfied with — which allegedly included some form of acknowledgement of the “good” the Nazi leader had done — West would continue to press people until he felt his views were validated, the music industry source says. “It sometimes became heated depending on the person,” says the source.

West took a particular interest in Nazi marketing and propaganda techniques, according to a second former longtime collaborator, who estimates in the four-plus years of working with West that the rapper spoke positively of Hitler at least half a dozen times.

“[West’s] pattern of speaking on this in the studio [or] workplace was reasonably consistent,” the longtime former collaborator claims. “If he felt you were trustworthy … there was a reasonably high likelihood that he would attempt to engage with you and evangelize his beliefs about Hitler and the Nazis to you.”

A third longtime music collaborator recalls having a brief, tense conversation with West over Hitler around 2014, with West allegedly trying to explain the “good” Hitler had done. “I think my exact words were, ‘So what if Hitler did some good shit. So what?’”

Others didn’t feel so comfortable challenging West. Although the former longtime collaborator says they found conversations and mentions of Hitler extremely troubling, they felt there was “absolutely zero reasonable ability” to push back without risking being fired. “When these things happened, if you still wanted a place in this group, you stuffed down your concerns, kept a smile on your face, and moved forward as if nothing bad had happened,” the former collaborator explains.

West praising Hitler stunned a former business associate, who claims during a high-level meeting in fall 2015 that West called Hitler a “marketing genius” within the first 15 minutes of the call. “In my 25-plus years of being in the workforce, I’ve never heard anybody say that name out loud in a business meeting,” the associate says.

To salvage the meeting, the businessperson recalls correcting West and attempting to shift the conversation, only for West to say, “No, [Hitler] really understood how to mobilize people in a way that no one ever has.” “Hearing that, it’s almost unfathomable that anyone would call [Hitler] anything other than a murderer,” the former business associate explains, adding it was “without question the most disgusting thing I’ve heard in my lifetime.”

The following year, West released “Famous,” a track that reignited his long-standing feud with Taylor Swift. An early version of the song that leaked online contained antisemitic lyrics and West gripes about not being able to talk about Hitler, The Wrap recently reported. “The world’s turning black slowly,” West raps. “Where you can call niggas ‘niggas,’ but you better not mention Hitler. So tell me who runs the labels, where the guns from?”