“A secret that made me very lonely,” he told the magazine.
Rolf Ake Mikael Nyqvist was born on Nov. 8, 1960, in Stockholm. His adoptive father was a lawyer and his mother was a writer.
In his 30s, Mr. Nyqvist set out to locate his biological parents with the little information he knew about them, first tracking down and meeting his mother only once, in a Stockholm cafe for an hour. He found his father, a pharmacist named Marcello, in Florence, Italy, he wrote in a 2010 autobiography.
“It’s life before and after I got my Italian family. The change was felt throughout my body,” he told Hemmets Journal about discovering his father and his two half sisters, adding, “I have accepted my background — it is no longer distressed or diffused.”
Mr. Nyqvist landed his breakthrough role at age 39, playing Rolf, an abusive alcoholic husband in the 2000 film “Together.” The Swedish movie about members of a leftist commune in suburban Stockholm in the 1970s led to his first nomination for a Guldbagge, the annual cinema awards in Sweden.
From there, Mr. Nyqvist was cast in leading roles on television shows and in films, including as Mikael Blomkvist, the fervent investigative reporter, in the original Swedish adaptation of the book series “The Girl With the Dragon Tattoo.” He also received bigger parts in blockbuster Hollywood movies, playing a deranged Swedish-born Russian nuclear strategist in the 2011 movie “Mission: Impossible — Ghost Protocol.”
In 2014, Mr. Nyqvist played another leading villain, Viggo Tarasov, a Russian mobster who battles a former hit man played by the actor Keanu Reeves in “John Wick.”
In addition to acting, Mr. Nyqvist wrote several books, including “Just After Dreaming,” an autobiography published in 2010 in which he described his search for his biological parents.
Mr. Nyqvist is survived by his wife, Catharina, and his children, Ellen and Arthur, who are both in their 20s.