Shahjahan Bhuiya, who hanged some of Bangladesh’s highest-profile death row inmates in exchange for reductions in his own robbery and murder sentences, then briefly became a TikTok star after his release from prison, died on Monday in Dhaka, the nation’s capital.

The national police said on Tuesday that the cause of death, in a hospital, had not been confirmed. Abul Kashem, Mr. Bhuiya’s landlord, said in an interview that he had driven Mr. Bhuiya to the hospital on Sunday after he complained of chest pains.

Last year, Mr. Bhuiya told the local news media that he was 74. But according to his national identity card, provided by Mr. Kashem, he was 66 at his death.

Mr. Bhuiya was sentenced to 42 years in prison for robbery and murder in 1991, the news media reported. But he was able to shave a decade off the sentence because of good behavior and in exchange for hanging fellow inmates. The authorities granted him early release last year.

In a memoir published afterward, “What the Life of a Hangman Was Like,” Mr. Bhuiya wrote that he had put 60 inmates to death. Prison officials have said that the correct figure was 26.

In that book and in interviews, he methodically recounted some of the executions. Some victims were men who had shaped the country’s modern history, including military officers convicted of assassinating the country’s founder and first president, Sheik Mujibur Rahman, in 1975. Another was Siddiqul Islam, the leader of a militant Islamic group, who was convicted of being involved in bombings in 2005.