David McCallum, the Scottish actor who played Illya Kuryakin on “The Man from U.N.C.L.E.” and appeared as eccentric medical examiner Donald “Ducky” Mallard on “NCIS” for two decades, died Monday. He was 90.

>> Read more trending news

McCallum died of natural causes in New York, according to Entertainment Weekly.

“NCIS” announced his death in a post on X, formerly known as Twitter. The announcement did not include any further information.

McCallum was the last remaining original cast member on “NCIS,” Deadline reported. As Mallard, McCallum portrayed a highly efficient investigator with a knack for psychological profiling, according to the entertainment news website.

He appeared in 457 episodes of the show from 2003 to 2023, according to IMDb.com.

“David lived a great, full, long life,” longtime “NCIS” star Mark Harmon said in a statement, according to Deadline. “I was in awe when I first met him and all of us on the show were honored to have toed a mark opposite him. My condolences go out to Katherine and his family.”

McCallum was hired in 1964 to play Kuryakin, the enigmatic, Russian partner to Robert Vaughn’s Napoleon Solo, on “The Man From U.N.C.L.E,” The New York Times reported. The show, a tongue-in-cheek look at secret agents, featured Vaughn and McCallum working for the United Network Command for Law and Enforcement, according to the newspaper.

He appeared in all 105 episodes of the series, which ran from 1964 to 1968, according to IMDb.com.

McCallum was born on Sept. 19, 1933, into a musical family in Glasgow, Scotland, the Times reported. His father was the first violinist for the Royal Philharmonic Orchestra in London; his mother, Dorothy Dorman, was a cellist.

He studied at the Royal Academy of Music and later attended Royal Academy of Dramatic Arts, Entertainment Weekly reported.

McCallum also played Judas Iscariot in “The Greatest Story Ever Told,” according to the Times.

McCallum married actress Jill Ireland in the spring of 1957, when both appeared in “Robbery Under Arms,” the Times reported. They had three children together, and Ireland made a few appearances on “The Man from U.N.C.L.E.”

They were divorced in 1967. Less than a year later, McCallum married Katherine Carpenter, a model. They were married for 56 years, according to the newspaper.

“NCIS” made McCallum a television star for the second time.

“In New York now I leave 15 minutes -- because I walk everywhere in New York -- between appointments because I am going to be stopped on the street to talk about ‘NCIS’ for at least 15 minutes,” he told BBC Radio in a 2009 interview.

McCallum also recorded four albums during the 1960s, one of which included the song “The Edge,” which Dr. Dre sampled to create the opening of “The Next Episode,” Entertainment Weekly reported. McCallum also published a novel in 2016, “Once a Crooked Man.”

ExpandAutoplay

Image 1 of 11

Through the years Scottish-born actor David McCallum as Jim Marston in the film 'Robbery Under Arms', 1957. (Photo by Silver Screen Collection/Getty Images) (Silver Screen Collection/Getty Images)

©2023 Cox Media Group