Melissa Rivers, the daughter of the late comedian Joan Rivers, is investigating her mother’s death following a routine throat procedure. TheWrap.com reports that Melissa Rivers has hired a team of attorneys to conduct the investigation.

The comedian, 81, died last month after a procedure performed at a clinic Aug. 28. After her death, there were reports that her personal physician was present and wasn’t authorized to practice at the center, the story notes.

“In order to fully determine the facts and circumstances surrounding the death of Joan Rivers, we confirm that our firm has been engaged by Melissa Rivers and her family,” Ben Rubinowitz, a partner at Gair, Gair, Conason, Steigman, Mackauf, Bloom & Rubinowitz, said in a statement Tuesday.

Rivers was given Propofol as an anesthesia medication, which is the same medication that is blamed for Michael Jackson’s death in 2009.

Melissa Rivers