Porsche looks set to launch a more extreme, track-focused derivative of the Panamera saloon.

The most hardcore derivative to date has been the 760bhp Turbo S E-Hybrid, which still closely resembles the standard 348bhp Panamera despite the high output of its V8-centered PHEV powertrain.

But new prototypes caught by Autocar spy photographers reveal that something more hardcore is in the works, which could possibly take the Turbo GT badge.

Spotted at the Nürburgring, the test mule wears a number of high-performance modifications including new vents in the front wings, a small gurney flap, a fixed spoiler, a reworked diffuser and round tailpipes. 

It also has a pair of stickers referencing the Nordschleife and another German circuit, the Bilster Berg Drive Resort, suggesting extreme testing is well under way.

Autocar’s photographers say the car sounds as if it remains powered by the V8, but it remains yet to be determined whether it is boosted by an electric motor.

However, the test mule was spotted running with two different suspension heights, suggesting it could be based on the E-Hybrid powertrain, as the Panamera's Active Ride Control system is exclusive to PHEV models.

Given its performance billing, the new model is likely to receive a significant bump in power over the Turbo S E-Hybrid, which could be netted through tweaks to both the car’s engine and motors.

The most powerful Porsche currently on sale is the 1020bhp Taycan Turbo GT electric saloon.

Inside, pictures show the new Panamera has been fitted with an RS-style roll cage behind the front seats, but the rear seats appear to remain in place – evidenced by the placement of a cuddly toy between the driver and front passenger.

It's possible that this cage could come as part of a track-focused Weissach option package, similar to that offered on the 911 GT3 and Taycan Turbo GT.

The development of new derivatives of the Panamera will be key to maintaining the model’s appeal, with its life cycle having been extended in a recent overhaul of Porsche’s business plan. 

The company has mothballed the SSP Sport platform that was due to underpin the electric third-generation Panamera. It will instead overhaul the ICE and hybrid versions to keep them running “well into the 2030s”, outgoing CEO Oliver Blume said on an investor’s call last month.