An autopsy shows the death of Victoria Siegel, the 18-year-old daughter of Orlando resort mogul David Siegel and his wife, Jackie, was an accident.

The report, released Wednesday by the Orange County Medical Examiner's Office, concluded Siegel's death in June was the result of methadone and sertraline toxicity. The examination found significant concentration of both drugs.

Victoria Siegel had previously undergone voluntary rehabilitation to shake her dependence on prescribed medication to control her seizures, a family attorney said.

Siegel was found unresponsive by a housekeeper at the family's Windermere mansion on June 6. She died the following day at Health Central Hospital.

David and Jackie Siegel were featured in the 2012 documentary, "The Queen of Versailles," which originally focused on the construction of the family's 90,000-square-foot home in Windermere. The family also appeared in a 2015 episode of "Celebrity Wife Swap." David Siegel is the founder of Orlando-based Westgate Resorts.

The couple had previously announced plans to start a foundation in Victoria's name to help troubled teens with addiction issues.

Information from The Associated Press was used in this report.