Multiple police vehicles and officers can be seen after a man’s body was found at 8am at an address Upfield Close.
The man, who police said was in his 60s, was declared dead at scene.
Upfield Close has been closed with cordons also in place in Hyperion Walk and Riverside Walk.
A police spokesman added: “An investigation is underway to establish the circumstances of his death and enquiries remain ongoing.
“A cordon remains in place at the address and the road is currently closed. Cordons are also in place in Hyperion Walk and Riverside Walk in Horley.
“We would like to thank local residents for your support and cooperation while we carry out further enquiries.”