The rescue mission went into full swing in Clacton, Essex, after neighbours told police the man had four pets.
It took a week for officers to find them among boxes and papers reaching up to the ceiling. They found unopened boxes of cat food and evidence the pets had been drinking dirty sink water.
The animals are now at rescue centres.
"Entering the property, it became clear as to why the cats were originally undetected," PCSO Dan Brown said.
"Sadly, the dead man had an extreme hoarding habit, with newspapers and boxes of canned goods reaching up to the ceiling, including boxes of unopened cat food.
"This made the home difficult and dangerous to move around in."
There was evidence to suggest the cats had been scratching at some of the boxes to get at the food inside.
However, as they did not seem keen to leave the property and could not be enticed out, humane traps had to be left.
"The situation at the house was very sad, and of course it was imperative that we got the cats out of the house as soon as possible," Mr Brown said.
"They were desperate for food and had resorted to drinking dirty water from a kitchen sink."
It took a week to rescue all four, now renamed Piglet, Peter, Tigger and Sir Scat Cat - a particularly nervous and frightened feline.
They are being looked after at the RSPCA's Southridge and Danaher shelters, waiting for new homes.
Four cats living in the home of a deceased "extreme hoarder" were rescued after spending a week evading RSPCA and police officers.