GAUHATI, India — Mahendra Nath Das was convicted of a murder so gruesome India's courts gave him a rare death sentence and the president rejected his plea for clemency. Only one thing is keeping him from the gallows: There is no hangman.

More than two decades have passed since any convict was executed in Assam, and with no qualified executioners remaining, officials in this northeastern state are scouring the rest of the country for a candidate.

In all of India, where the death penalty is only by hanging and imposed only in the "rarest of rare" cases, there have been only two hangings in the past 15 years.

Das' conviction for publicly decapitating a victim with a machete could make his the third.

"We have started the process of putting up the gallows," said Brojen Das, the jailer of the prison at Jorhat, 300 kilometers east of Gauhati, who shares a common regional surname with the condemned man.

But it is unclear when an executioner will be found to use it.

Prison authorities have written to their counterparts in the states of Uttar Pradesh and West Bengal searching for a hangman, but have so far gotten no response, said S. Thakuria, Assam's top prison official.

Qualified executioners — who know how to prepare the rope and tie the knot so as to cause a swift death — are scarce in India. The last hanging took place in 2004, when a security guard was hanged in a Kolkata jail for the rape and murder of a teenage girl.

Nata Mullick, India's most famous hangman, came out of retirement at age 84 to carry out that execution, earning $435 and a job for his grandson as a maintenance worker at the jail.

A third generation hangman, Mullick executed 25 of the 55 people who died on the gallows since India gained independence in 1947.

He would run repeated dry runs, using sandbags the same weight as the condemned prisoner. He waxed the rope with soap and ripe bananas and tied it with five knots, hoping his preparations would keep the pain to a minimum and ensure the prisoner's head was not severed during the drop from the gallows.

"It's an art: Your skills need to be honed," Mullick said in a 2007 interview.

But Mullick died in 2009. With the hangman's job a far from glamorous profession, and the work so sporadic, few have risen to take his place. Local media said there might be one or two hangmen still around nationally, including Mullick's son, Mahadeb.

The search could have implications for other death row prisoners, including Mohammed Ajmal Kasab, the lone surviving gunman from the 2008 Mumbai terror attack, and Afzal Guru, who was convicted in the 2001 attack on parliament that killed 14 people.

Mahendra Das' crime traumatized Assam.

On April 24, 1996, he snuck up behind Hara Kunta as the rival official in the local transporter's union sipped tea at a shop in a busy market in Assam's capital, Gauhati.

With a swing of his machete, Das decapitated Kunta. Then he carried the bloody head by the hair to a nearby police station screaming, "I have killed him."

Courts ruled that the public nature of the killing, combined with Das' horrifying walk through the streets, warranted the death penalty.

Last month, President Pratibha Patil agreed, refusing a plea for clemency, and condemning Das to be the first person to be executed in Assam since a prisoner convicted of three murders was hanged in 1990.

Though there are no legal options left, his family continues to appeal for mercy.

"My son has already spent 15 years in jail, why kill him now," Mahendra Das' 75-year-old mother, Kusum Bala, told a local newspaper.

The victim's family is impatient for the execution.

"There is no point showing sympathy to a killer like him," Hara Kanta's daughter-in-law Sarada Das said.

If no professional hangman can be found, prison rules would allow a convict to volunteer to carry out the execution, said Brojen Das, the jailer. No one has yet come forward, he said.

For now, Mahendra Das, 45, spends his days in a 1.8 meter by 3.7 meter prison cell, where he will stay until an executioner can be located, Brojen Das said.

"He is hoping against hope that somehow he can be saved," he said.