Police said there was no sign of forced entry at his Bronx appartment and a 9mm gun was found.
The music executive had been going through a divorce and had financial problems.
His death at the age of only 44 has left the entertainment world in shock.
'Fiddy' described the music mogul, who also helped the careers of Mariah Carey and Missy Elliot, as a "good friend and adviser".
A statement from the artist said: "Chris has been an important part of my business and personal growth for a decade.
"He was a good friend and adviser who helped me develop as an artist and businessman.
"My prayers are with his family. He will be greatly missed."
Meanwhile, Rihanna posted: "Rest peacefully Chris Lighty, my prayers go out to family and loved ones! Dear God please have mercy."
Sean 'Diddy' Combs said he was "in shock" and Mary J Blige tweeted: "You never know what can send a person over the edge or make them want to keep living. Take it easy on people."
Chris' successful career came after a difficult childhood, being raised by a single mum along with five siblings. He started out working for Def Jam mogul Russell Simmons before going on to start his company Violator in the Nineties.