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.

Mr. Bhuiya died at a hospital in Dhaka, the capital, the national police said on Tuesday, adding that the cause was unconfirmed. Abul Kashem, his 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 Mr. Bhuiya’s national identity card, provided by Mr. Kashem, he was 66 at the time of his death.

Mr. Bhuiya was sentenced to 42 years in prison for robbery and murder in 1991, the local 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 that he published after his release, “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, Mr. Bhuiya methodically recounted some of the executions. Some 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.

He also put to death two opposition leaders, Salahuddin Quader Chowdhury and Ali Ahsan Mohammad Mojaheed, who were convicted of war crimes committed during the 1971 war that resulted in Bangladesh’s independence from Pakistan, according to local police.

“Don’t let anyone take my picture,” Mr. Bhuiya quoted the Islamic group leader, Siddiqul Islam, as saying just before he was executed.

“I haven’t done anything wrong in my life,” said another death row inmate, Ershad Shikder, a politician convicted of murder, according to Mr. Bhuiya. “Pray for me.”

After his release from prison, Mr. Bhuiya published his book and briefly became a TikTok star. His videos often featured his sexually suggestive conversations with young women.

Mohammad Shahjahan Bhuiya was born on Jan. 1, 1958, according to his identification card.

His hometown was a village in the district of Narsingdi, in central Bangladesh, and he had three sisters, he wrote in his memoir. Other information about his family was not immediately available.

He enlisted in the army but dropped out when he could not complete the rigorous training program, he wrote. He later rose the ranks of the Communist Party of Bangladesh to become the Narsingdi district’s branch president.

Information about his robbery and murder sentence was not immediately available. What is clear is that he was released 10 years early in June 2023.

At a news conference after his release, Mahbubul Islam, the jailer of Dhaka Central Jail, said that Mr. Bhuiya’s sentence had been shortened in part for good behavior and the executions he had conducted. He received a two-month reduction for each execution, Mr. Islam said.

A prisoner can have their term reduced by up to a quarter for carrying out executions and other prison tasks, as well as for good behavior, Suvas Kumar Ghose, a senior jail official at Dhaka Central Jail, said in an interview.

All executions in Bangladesh are carried out by long-serving prisoners who are selected by the authorities, said Juliette Rousselot, the deputy Asia director at the International Federation for Human Rights, an advocacy group based in Paris. Executioners can have their sentences shortened or receive incentives like better prison accommodation, she said.

Bangladesh sentences hundreds of prisoners to death every year, and about 2,400 prisoners were on death row as of this year, according to Amnesty International, an advocacy group based in London. But in a given year it typically carries out only a handful of executions.

In addition to making TikTok videos after his release from prison, Mr. Bhuiya ran a tea stall, one of his sisters, Firoza Begum, said in an interview. She said he had little contact with his family for decades, and that his other siblings had died. No other information about survivors was available.

Mr. Bhuiya has appeared generally blasé about the executions he carried out, even expressing pride for his role in putting to death the politicians convicted of war crimes and the military officers who assassinated the president.

Mr. Bhuiya said at a news conference after his release that he had been given the job of hangman because “I was courageous.”

He said that couldn’t help but feel a little pity every time he put someone to death. But he added: “Even if I didn’t hang them, someone else would have.”

After three decades in jail, he felt like “a newborn baby from my mother’s womb,” he added. “My goal now is to live well.”