Aaron Carter’s neighbours reportedly heard one of his employees screaming “he’s dead, he’s dead” when she discovered the singer dead.
A friend also told The US Sun on Sunday they believe the late singer, 34, did not take his life and he had plans to go into the studio next week to record new music.
Carter’s mum Jane is believed to be travelling to Aaron’s home in Lancaster, California, from her house in Florida.
A witness at the scene of Carter’s death on Saturday afternoon said it was “chaos” due to police cars and news vans, and residents lining the street.
Neighbour Tony Cheval, a local photojournalist, told The US Sun: “I have a police scanner for work and heard the call come in that there was an unresponsive male in the bathtub.
“My wife is a nurse and we headed over and banged on the door, she had her AED (automated external defibrillator) with her.
“A woman answered the door and was screaming, ‘he’s dead, he’s dead’ but wouldn’t let us in because she’d already called the cops.”
They added about Carter’s on-off fiancée Melanie Martin, 30, turning up at the scene: “I spoke to Melanie afterwards and she said it was his maid, and questioned why she wouldn’t let us in.
“Melanie drove up from Orange County – she was distraught.”
A second witness said Carter’s house-sitter, who is thought to have made the 911 call that alerted police to his death, was seen looking “shaken” and spent time speaking with officers.
They said: “The house-sitter was the only person behind the police tape for long.
“Melanie had to wait hours before police would even tell her anything, and she was desperate to see their many pet dogs still in the house.”
Carter enrolled in a month-long outpatient programme at the Lionrock rehab centre in Los Angeles in September, but there have been reports friends fear he may have suffered a relapse after battling addiction issues for more than 10 years.