A suspected cannabis farmer fled a burning house in Portslade as firefighters and police arrived.
The man left by the back of the house in Old Shoreham Road, Portslade, and ran off leaving about 400 plants behind.
Sussex Police said that detectives wanted to interview the man.
The alarm was raised by neighbours who spotted smoke pouring from the property just before 5.30pm on Friday (22 April).
A police spokesman described it as a well-organised factory with several rooms set up with electronics and lamps and the loft set aside for storage.
The fire is believed to have started because of an electrical fault, is believed to have caused the fire.