The series was the brainchild of Lisa Tobin, the executive producer of Times audio; Sam Dolnick, an assistant managing editor; and Mr. Mills, according to two people with knowledge of the podcast. The first installment came out on April 19, 2018, as part of an episode of The Daily. The first words of “Caliphate” were an exchange between Ms. Callimachi and Mr. Chaudhry taken from a 2016 interview recorded in Canada.
“How does ISIS prepare you to kill people?” Ms. Callimachi asked.
Mr. Chaudhry, who said he had assumed the name Abu Huzayfah as a member of the Islamic State, replied haltingly, saying, “We had dolls to practice on.” In later installments, he said he took part in lashings, as well as the killings of two people, describing the executions in grisly detail.
His apparent confession created a firestorm in Canada. Politicians asked why a supposed Islamic State executioner was living quietly within the nation’s borders. Upon his Sept. 25 arrest, the Royal Canadian Mounted Police charged Mr. Chaudhry under a law usually applied to people who make false terroristic threats.
The hoax charge cast doubt on “Caliphate,” but The Times was initially supportive. “The uncertainty about Abu Huzayfah’s story is central to every episode of ‘Caliphate’ that featured him,” a Times spokeswoman said in a Sept. 26 statement. Days later, The Times announced that it would review the series, which had been a popular and critical success in 2018, hitting No. 1 on Apple’s list of most downloaded podcasts and later winning an Overseas Press Club prize and a Peabody Award.
There had been warning signs during — and even before — the months when “Caliphate” episodes came out each Thursday. In a 2017 interview with the Canadian Broadcasting Corporation, Mr. Chaudhry gave an account of his time with the Islamic State that differed greatly from what he had told Ms. Callimachi. In that CBC interview, he said he had “witnessed violence on a scale he could never have imagined,” but did not say he had taken part.
In another interview, published on the CBC website on May 11, 2018, Mr. Chaudhry recanted his confession. When asked why he had told The Times that he had participated in atrocities, he said, “I was being childish. I was describing what I saw and, basically, I was close enough to think it was me.”
Behind the scenes at The Times, as was previously reported by the paper’s media columnist, Ben Smith, high-level editors had raised concerns about “Caliphate” before it was released.