Kim worked as a stylist for Brandy Melville, Ray J's sister, during the early 2000s and briefly dated Ray J
In 2006, Kevin Blatt claims he was offered the chance to buy their sex tape
Kim Kardashian and Ray J have yet to respond to requests for comment, but both stars have routinely denied that they had anything to do with the video's release.
Blatt, now 52, said a childhood friend who was employed by Adult Video News at the time told him of the tape's existence.
While Blatt said he was not familiar with Ray J, he agreed to meet the rapper - who is the brother of R&B singer Brandy Melville - for lunch at a Cheesecake Factory to learn more about the contents of the video.
Blatt remembered a Lamborghini driver walking into the restaurant in a Lamborghini.
Blatt and his friend were then told by Ray J, who Blatt described as "very funny" and sharp, of a video that he'd taken of a sexual encounter he'd had with a woman that neither Blatt nor his friend had heard of.
It would turn out that the woman in question was Kim Kardashian, a then-relatively unknown fashion stylist who was close friends with reality TV star Paris Hilton.
Two years earlier, Blatt had made his name in the sordid business of celebrity sex tape brokering by facilitating the release of Paris Hilton's sex tape with Rick Salomon, One Night In Paris.
Ray J explained that Kim's tape was filmed in Cabo, Mexico, in 2002 when they were celebrating her 22nd birthday.