Two men in their twenties have died after their car smashed into a tree in Syon Lane, Isleworth this morning.
The accident occurred at about 1.10am as their car - a silver Porsche 911 Turbo - was travelling south and left the road before colliding with the tree.
At this early stage police believe no other vehicle was involved in the incident. London Ambulance Service and London Fire Brigade attended the scene and the two occupants of the vehicle were pronounced dead at the scene.
The men who died are believed to 28 and 26. Police are awaiting formal identification before releasing their names and next of kin have been informed.
A post mortem for both men has been scheduled for Monday June 29 at Fulham Mortuary.
Inspector Dave Toms-Sheridan from the Collision Investigation Unit based at Hampton Traffic Garage, said: "I would urge anyone who witnessed this incident to come forward and speak to us.
"In particular, I am keen to speak to the occupants of a black car which witnesses have said stopped near to the scene moments after the Porsche left the road. At this stage there is nothing to suggest any other vehicle was involved in this incident, but the occupants of this car could prove to be vital witnesses."
Anyone with information is asked to contact the police Witness Appeal Line on 0208 941 9011 or speak to Crimestoppers, anonymously, on 0800 555 111.