'NCIS: Los Angeles' Actor Ravil Isyanov Dead at 59 After Cancer Battle: 'He Was a True Gentleman'

Ravil Isyanov, who appeared on the CBS series NCIS: Los Angeles, has died. He was 59.

Isyanov died at his Los Angeles home on Sept. 29. His manager, Frederick Levy, tells PEOPLE that the star was battling cancer, although he was unclear on what kind.

"Ravil was one of a kind. He was a true gentleman, extremely generous and incredibly talented," says Levy.

The Russian-born actor was perhaps best known to fans for playing mobster Anatoli Kirkin in NCIS: Los Angeles, during which he received his cancer diagnosis. Levy says Isyanov gave producers a heads up about his declining health.

His manager recalls, "He knew that his future looked bleak because of the cancer and he let producers know, and if they wanted to write him off, they might want to do it, soon… I just thought it was really sweet that they were able to give him a proper send off."

Isyanov also appeared in the movies Transformers: Dark of the Moon and Defiance.

The actor spent much of his childhood in the Greater Moscow area, where he studied music, ballet, and theater. He served two years in the Soviet Air Force, followed by time spent at the Moscow Arts Theatre School and the British American Drama Academy.

In 1998, Isyanov arrived in L.A. to pursue acting. In addition to his seven-episode stint on NCIS: Los Angeles, he also made guest appearances on TV shows The Last Ship, The Americans, and Agents of S.H.I.E.L.D.

Isyanov's final roles will be in the upcoming Marilyn Monroe biopic Blonde, in which he played Billy Wilder alongside stars Ana De Armas and Bobby Cannavale; and in 25 Cents Per Minute, which is expected to be released this year.

He is survived by his wife Erika, daughter Gulya, son-in-law Marios, and grandchildren Cassandra and Nikita. Isyanov is also survived by stepdaughter Aneta, her husband Jon, and step-grandchildren Mila and Tali.