Lee Grivas, the 26-year-old boyfriend of Christina Applegate, was found dead in his apartment on July by a neighbor.
He was discovered, alone, in the living room of his Hollywood apartment, and was pronounced dead at 5:25 p.m.
Although the autopsy has not been completed as of yet, sources report there were no visible signs of trauma.
Christina Applegate and Lee Grivas dated on and off for years after they met through a mutual friend, a dancer in her Broadway show "Sweet Charity."
"I am profoundly saddened," Christina Applegate said in a statement.
"Lee was an incredible human being who was an extremely important and beautiful part of my life. He is missed beyond words. He touched so many and I feel much sadness for his mother, father, brother, and all of his family and friends."