According to the website, she began vomiting early Sunday morning and told family members she was feeling very ill. (She was "found unresponsive" Sunday morning at her Hollywood Hills home and was pronounced dead at 10:04 a.m. at Cedars-Sinai Medical Center in Los Angeles.)
TMZ also reports that "various prescriptions were found in Murphy's home -- written for her, her husband Simon Monjack and her mom."
The site quotes a source as saying, "There were a lot ... a lot of prescriptions in the house."
An official cause of death may not be determined for some time, since toxicology tests will be required, but "it appears to be natural," L.A. Assistant Chief Coroner Ed Winter tells UsMagazine.com. He said an autopsy is set to take place in the next two days.
The Los Angeles Times reported that police said Murphy died of cardiac arrest.
But father Angelo Bertolotti tells Us he doesn't buy it.
"Brittany never had a heart problem before, so I don't understand how she died," he tells Us. "This doesn't make sense to me."