Drake seems to think there's some shadiness behind Kendrick Lamar's monster hit, "Not Like Us" ... and he's filed legal docs to investigate how it got so big.

Of course, "Not Like Us" is the song that effectively ended the Kendrick and Drake beef ... because its popularity buried Drake -- but now, he's alleging Universal Music Group used bots and a payola scheme to pump up the song.

According to the docs, obtained by TMZ Hip Hop, Drake says an "inside source" told him UMG made "covert payments" to multiple platforms, including radio stations, to play and promote the hell outta "Not Like Us." Legally, that's known as payola, and it's prohibited by the FCC.

Drake points out UMG has paid settlements in the past for this kinda thing ... like in 2006, when the label paid $12 million to the NY Attorney General's Office for a "pay for play" scheme.

In the docs, he also claims a whistleblower has accused UMG management of spending thousands in May 2024 on "bots" in order to get the song to 30 million streams on Spotify -- and it also paid social media influencers to promote the song. He alleges the label dropped all copyright restrictions so the influencers could repeatedly post the song ... helping it spread like wildfire.

Drake has some huge legal goals here -- he says he's filing this suit just to get a full understanding of how UMG funneled payments to iHeartRadio and its network of stations. Once he has that info, according to the docs, he's gearing up to file a civil fraud and racketeering case against UMG and any co-conspirators.

Remember, "Not Like Us" famously includes the lyric where Kendrick calls Drake a "certified pedophile" ... and Drake says he already has grounds to sue UMG for defamation among other things.