The British musician featured on an early version of Drake's 2014 tune 0 to 100/The Catch Up, but it was never officially released after the Canadian hip-hop star failed to secure the song rights from James.
Now the singer has opened up about the snub, revealing he turned down the approval request because he had hoped to work directly with Drake, instead of just having his work sampled for the rapper's latest album, Views.
"I sent them some stuff just hoping to just do a collaboration of some kind," James recalls on Spotify's Secret Genius show, "and I got an email the day before 0 to 100/The Catch Up came out. It just said, 'Hey, we're using this beat you made from, like, four years ago'. I only sent it as a collaborative idea, not to be sampled on a record.
"I was like, 'No!' So I got them to take it off."
James insists he stands by his decision, which was made on principle, but he was stunned when he learned how much it had cost him.
He says, "I remember having a conversation with my publisher later, and saying, 'What did you think of that decision?' - because, you know, that was a massive album. I asked how much money exactly I turned down by doing that. I spat out my drink."
Blake, who recently worked with Beyonce, goes on to admit he actually liked the way his work had been sampled, but continues, "I just did it as a matter of principle at the time. I really liked it. And I think had they come to me beforehand and said, 'We really want to use this, what do you think?', I probably would have said yes."
He warns other big artists not to take his music contributions for granted: "Just because someone has an impressive amount of clout and a global platform, I don't give a s**t about that; I just want to make good music with people. And it was good music. But just ask me."