Lamborghini Veneno revealed

Lamborghini has stolen the show in Switzerland with a radical new coupe that's even more extreme than its Aventador flagship.

The Veneno is set to upstage Ferrari's replacement for the Enzo and McLaren's P1 flagship, banking on a wicked body makeover and a tuned Aventador vee-12 engine with a whacking 550 kiloWatts.

Early details of the Veneno emerge as pictures of the Italian stallion leak to the web on the eve of the 2013 Geneva auto salon - and ahead of the reveal of Ferrari and McLaren's highly-touted new heroes. Only three cars are being built and all three are already sold - two set for shipping to the USA - despite a pricetag around $4 million.

Lamborghini has not included the Veneno in its pre-show push, concentrating instead on its 50th anniversary and the unveiling of two Aventador LP700-4s in special colours, Rosso Mars for a coupe and Bianco Isis for a roadster, on an enlarged stand at the first European motor show of 2013.

But it is promising a "breathtaking surprise" at 11am, Geneva time, with the introduction of a "world premiere" by company chief Stephan Winkelmann. So the Veneno is real, not a web hoax like the claimed preview of the Ferrari F150 last month.

Judging from the leaked Lamborghini pictures, the Veneno has a massively re-styled body intended to cut deeply through the air and deliver extra downforce, as well as huge venting behind the cockpit to keep the engine cool.

Not surprisingly, there are lashings of lightweight carbonfibre and the promise of a top speed better than 380km/h. The Carsguide crew will have more details once the car is officially unveiled at the show.

This reporter is on Twitter @paulwardgover