There is no longer a universal “song of the summer,” but if you’re into rap music, Fenix Flexin’s “Rubberz” is a contender. Officially released in June, it currently sits at No. 58 on the Billboard Hot 100 and has a music video with 7 million views. Lyrically, it boasts about cash and jewelry, with double entendres for braggadocio and depression.

However, there are two interesting twists to “Rubberz.” First, it’s not a rap song at all; it’s a synth-pop tune that would fit in an 80s playlist. Secondly, since its release, it has been the focus of accusations that it was completely or partially AI-generated.

The argument reached a peak this weekend after an independent music producer claimed he’d figured out how Fenix had made “Rubberz” and that his labelmate Tyga also used a little-known generative AI music app. The service’s new built-in detector is now flagging the songs made by both artists as likely AI-generated.

People were suspicious of Fenix from the beginning; “Rubberz” is not only an unusual genre shift for the artist, it also doesn’t sound like his voice in the song. As the summer continued, music media debated whether “Rubberz” had been AI-generated. But none of the well-known AI music detectors flagged it and Fenix denied it.

Then, things shifted suddenly on Thursday when a music producer named Medasin posted a video claiming he’d figured out how Fenix used AI to make the track. By using tags like “80s synthwave” and prompting the app to write lyrics about a “rapper lifestyle,” Medasin got a similar-sounding song with lyrics that bear more than a passing resemblance to “Rubberz.”