Spyder7 reckons the luxury brand is looking into a high-performance crossover, which could be revealed in production form as early as 2020 before going on sale the following year.
The publication earmarks the LF-1 Limitless concept (pictured) revealed at this year's Detroit motor show as a preview for the rumoured SUV.
Under the fancy skin, the production model would allegedly ride on a version of the Toyota New Global Architecture (TNGA) platform, variations of which will underpin every model in the Lexus and Toyota range in the coming years.
According to the report, entry-level versions will be powered by the twin-turbo 3.5-litre V6 or 3.5-litre V6 hybrid currently offered in the LS limousine. The twin-turbo engine is rumoured to make around 430PS (316kW), which is a little up on the LS500's 310kW power output.
The go-fast version, potentially branded as an 'F' model, is said to be powered by a 4.0-litre twin-turbo V8 rumoured to feature in the unconfirmed LC F and LS F halo models.
This engine is claimed to make around 670PS (493kW), putting the F-branded SUV right up there with the Urus (478kW) in the power stakes.
None of the Japanese website's claims have been substantiated yet, though it was widely reported the LF-1 previewed an upcoming SUV flagship, while a recent trademark filing in the US hinted at a new Lexus 'LQ'.
What? But Lexus only uses 'X' for its SUVs, right? It's believed the 'Q' could be used to signify a crossover 'coupe'.
In the meantime, we'll have to wait and see.