Lisa Robin Kelly’s death last week has left authorities feeling uneasy.

The Los Angeles County Coroner's Office is investigating the "That '70s Show" star's mysterious death, her manager Craig Wyckoff told FOX411.

In a move that Wyckoff called "not routine" the office is looking into exactly what transpired on Aug. 14 when 43-year-old Kelly died in her sleep at a California rehab facility. TMZ first reported that authorities were looking into her death.

"It's not routine, but in the state of California, if a woman is found dead under a certain age, then they have to do an investigation," he explained.

Earlier media reports claimed that the coroner's office was suspicious because they were not immediately notified about Kelly's death, but Wyckoff said that was not the case.

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"She did die Wednesday night, but everyone was notified immediately," he said.

Wyckoff added that he had heard that there were "other instances of unexplained deaths" at the same rehab facility, but he made it clear he was unsure if there is any truth to those rumors.

Kelly’s autopsy was completed over the weekend, but her toxicology results won't be back for about five weeks.

"I know the family is planning on having Lisa cremated, and then [having] her ashes brought back to North Carolina for a funeral ceremony," he said.

Wyckoff added that her rocky relationship with her husband has complicated some of the proceedings following her death.

"Lisa [was] legally separated from her husband and there was a restraining order against him. And yet in the state of California, since the divorce was not finalized yet, he is the legal the next of kin," he said. "That complicates things with her remains and what happens to her because it becomes his decision."

Kelly portrayed Laurie Forman, sister of Topher Grace's lead character Eric, on “That ‘70s Show.” It concluded in 2006.

Unlike some of her co-stars — Grace, Ashton Kutcher and Laura Prepon — Kelly fell out of the spotlight after appearing on the sitcom until she started making headlines for personal troubles.

Since Kelly's role on "That '70s Show" wrapped, she was often in the news for her legal battles.

The Associated Press contributed to this report.