Casey Johnson, socialite and heiress to the Johnson & Johnson fortune, may have been dead inside her Los Angeles home for days before her body was found Monday.
TMZ quoted law enforcement sources as saying it appeared the 30-year-old had been dead for "several days" and that police had opened a death investigation.
Johnson had recently announced her engagement to reality TV star Tila Tequila. Tequila told TMZ Monday evening that the two had fought last week and that she was unable to reach Johnson Dec. 29 after she left her dogs at Tequila's house. The reality star told TMZ that Johnson's phone had been turned off ever since.
"I can't stop these haunting visions of her and I," Tequila tweeted early this morning. "We made such a lovely couple, only beginning to spend the rest of our lives together..."
Johnson, the daughter of New York Jets owner Woody Johnson, appears to have last tweeted shortly after 1 a.m. Dec. 29.
The Johnson family released a statement, The Associated Press reported, saying it's "mourning its tragic loss, and asks for privacy during this very difficult time."
Police said Monday that Johnson appears to have died of natural causes.
"Our officers conducted a preliminary investigation which appears to be an apparent natural death,'' Los Angeles Police Department spokeswoman Officer Sara Faden said. "There was no evidence of any foul play and the case is now being handled by the coroners, pending a toxicology report.''
Police responded to a call reporting that someone had died at 910 N. Orlando Ave., between Melrose Avenue and Santa Monica Boulevard near West Hollywood, at 11:51 a.m., Faden said.
Los Angeles Fire Department firefighters also responded to the call, and they conducted an investigation and determined that Johnson had died, the LAPD spokeswoman said.
Last month, Johnson and Tequila, the star of "A Shot at Love With Tila Tequila," which ran for two seasons on MTV, had announced their engagement in an online video, and thefrisky.com reported that the two showed up at a party together where Tequila showed off a large ring, saying, "It's a 17-carat diamond ring from my baby. My baby is a billionaire!"
Johnson was arrested Nov. 30 on felony charges of theft and receiving stolen property, accused of taking $22,000 worth of jewelry, underwear and other items from Jasmine Lennard, a model and British reality TV star.
The Associated Press and ABC News' Sarah Netter contributed to this report.