A Canadian orchestra launched a sexual harassment investigation after receiving a complaint that names renowned conductor Charles Dutoit, a spokesman said Sunday.

The probe by the Montreal Symphony Orchestra, where Dutoit served as music director for nearly 25 years, comes after the Associated Press on Thursday reported allegations against him by three opera singers and a classical musician who said he sexually assaulted them in incidents between 1985 and 2010.

Dutoit’s office issued a statement saying those allegations ‘‘have absolutely no basis in truth.’’ An e-mail to his office seeking comment on the new complaint was not immediately returned Sunday.