The singer was discovered underwater and unconscious in her Los Angeles hotel room on Saturday (February 11). However, suggestions that she drowned have been called into question following reports that there was very little water in her lungs.
It has now been alleged that police found bottles of six different types of prescription drugs in Houston's Beverly Hilton suite, which could have in some way contributed to her death.
These included Xanax, which family sources claimed in the immediate aftermath of her death that she had been taking at the time.
However, TMZ has suggested that the amount of pills found in the room may have been exaggerated.
According to The Sun, coroners will request copies of Houston's medical records and compare them with bottles they discovered, hoping to determine whether she obtained the drugs illegally.
"[Authorities] need to determine that no-one is criminally negligent," a source said. "There still could be charges in this case."
The publication adds that some pills are believed to have come from the Mickey Fine pharmacy, where Michael Jackson had numerous prescriptions filled for Demerol and other drugs.
An autopsy of Houston's body ascertained that there were "no signs of trauma" or "foul play", though the full findings have been placed on hold for up to eight weeks as police await toxicology results.
Authorities have confirmed that Houston's death is "not a criminal investigation" at present.
View Whitney's life in pictures below: