Toni Braxton's Niece Lauren's Cause of Death Revealed

The cause of death of Toni Braxton's niece Lauren has now been revealed.

The 24-year-old, who passed away back in April, died of a heroin overdose and fentanyl intoxication, E! News reported Thursday.

According to police reports obtained by TMZ, on April 29, a friend of Lauren's claimed she was talking with her in the kitchen and went upstairs for just 10 minutes. The friend told the cops that when she returned to the kitchen, Lauren was on the floor and unresponsive.

After receiving a 911 call, Lauren was found unresponsive by law enforcement upon arrival. She was pronounced dead by paramedics.

However, the official autopsy results seem to contradict the claim made by Lauren's father and Toni's brother, Michael Conrad Braxton Jr., who told TMZ her death was related to a heart condition.

Michael, 50, is the only boy among the Braxton siblings. He and Toni, 51, are the elder siblings to Traci, 48, Towanda, 45, Trina, 44, and Tamar, 42. Michael has appeared on episodes of his sisters' reality show "Braxton Family Values."

Following Lauren's death in April, the family released a joint statement: "We ask that you please respect the family's privacy in this time of sadness and loss."

Traci told TMZ: "LoLo was more than my niece, she was my daughter; and I, my son and husband are truly heartbroken over her passing."

Trina also spoke about her niece, posting an Instagram tribute, below. "God sent me another angel!" she captioned the pic. "Rest in Heaven Lauren 'LoLo' Braxton."