While the death of Russell Armstrong, estranged husband of ‘Real Housewives of Beverly Hills’ star Taylor Armstrong, has officially been ruled a suicide, a member of his family believes foul play may have been to blame, ‘Today‘ reports.

Armstrong was found dead in his Bel Air home on August 15 after apparently hanging himself. But Armstrong’s sister, Laurie Kelsoe, believes it was murder.

“From the minute I got the call, I knew that it was not suicide,” Kelsoe said, arguing that Armstrong would have never willingly left his children behind.

Armstrong’s family has vowed to hire a private investigator in order to uncover “the truth” behind his death.

[Today]