A band called Artikal Sound System just filed suit against the British pop star -- who's absolutely blown up over the past couple years of the pandemic with the help of her new album, and this track by extension ... one that's dominated the charts and streaming game.

Unfortunately for DL ... these guys are claiming she ripped off the catchy tune from their own reggae song, "Live Your Life," which they dropped in 2017 ... to some notable success.

This is a simple allegation of copyright infringement. According to the docs, obtained by TMZ, Artikal simply states ... Dua and her team heard their earworm pre-2020 (when they started writing "Levitating") and trotted out a carbon copy.

There's nothing laid out in their claim to explain *why* they believe that to be the case ... but presumably, that'll get hashed out in court as this thing plays out.

We'll say this ... the two songs do sound awfully similar, especially the chorus. Different lyrics, obviously, but the beat comes across as damn near the same -- and Artikal obviously felt strong enough about this to sue.

In addition to Dua herself, Artikal has named Warner Records (her label) and others as defendants -- and they're asking for any profits they may have made off of "Levitating," plus damages.