The American Guild of Musical Artists (AGMA) has opened its own independent investigation into allegations against opera star Plácido Domingo.

The organization made the announcement on Friday, noting that it would be launching a wide-ranging investigation in light of the fact that many of its signatory companies were unwilling or did not provide the union with sufficient assurances about the scope of their own investigations.

“Given the uncertainty surrounding the investigations of our signatory companies, AGMA’s internal investigation will not be limited to conduct that occurred at a specific company or at a particular time,” said AGMA National Executive Director Len Egert per AGMA’s official website. “Our investigation will also examine the systemic failures within the industry that could have allowed this conduct, if substantiated, to continue unchallenged for decades. In light of the seriousness of the allegations, and the number of AGMA members who may have been affected, we believe this investigation is necessary at this time.”

The Los Angeles Opera is the only company currently engaged in an independent investigation on the actions of Domingo, though the company has not given much information on the process. Meanwhile, the Washington National Opera, where Domingo was once General Director, has not launched any such investigation, noting that it has not been associated with the famed singer for several years.