The Los Angeles coroner’s office has received phone calls and emails saying that the star was unlawfully killed.
Individuals claiming to be members of Bobby Brown’s family have also contacted the coroner, while one claims to hold information to back up the murder theory.
One caller said they had a theory about a relative who may have been involved in Houston’s death.
But officials have refused to comment on the allegations and a recent report said Houston’s death will probably be deemed an accident.
Houston died, aged 48, at the Beverly Hilton Hotel on February 11.
The cause of her death has not been released, but foul play and trauma have been ruled out.
Houston’s family believe her death was an accident, but her former sister-in-law Leolah Brown said: “I believe Whitney’s death was not accidental.”
She added: ”It’s very important to know that she did not just pass away like that. No. And if it’s the last thing that I do, I’m going to find out what truly happened to my sister.”
But a source has previously said: “She had no marks on her body whatsoever to indicate a struggle, and she was the furthest thing from trying to kill herself.”