About 120 people were evacuated on Tuesday after a fire broke out in Tuen Mun.
Police were alerted at about 5am that there was a fire in a flat in Block 1 of Elegance Garden.
Officers said they forced open the door and put out the fire they encountered inside the flat.
A short time later, a man, 51, was found lying on the ground between blocks 1 and 2 at the residential complex.
He was certified dead at the scene and was believed to have fallen from height.
The force said the death and the fire were connected, adding that a suicide note had been found.
Officers were looking into the cause of the fire, along with the Fire Services Department.