It is a rare one who can say granddad used to be a hangman, let alone one she reveres and loves deeply.

But Ms Poojaa Darshan Kaur Gill hails with pride her grandfather, Mr Darshan Singh, Singapore's most well-known executioner.

"I did all my firsts with him - my first trip to school, to the mall, the zoo and my first bicycle ride, as he was the one who taught me," said the 26-year-old model and former national athlete.

Last month, she and her mother, Jasmine, hosted a birthday bash with family and friends in a Bedok condominium for Mr Singh when he turned 85.

These days, he needs a wheelchair to move around and suffers from dementia.

"We held the event to show gratitude to Darshan and to enable him to connect with his close friends and relatives, " she said.

Mr Singh, a retired prison officer, served as state executioner for more than 25 years until 2005.

He had been an assistant to the previous executioner, who left in 1972, necessitating an advertisement from the Prisons Department in the press for a replacement.

Enter Mr Singh, who, in his time, executed many from a gallery of the infamous, from child-killer Adrian Lim and his two female accomplices, to Anthony Ler, who had paid a teenager to kill his wife.

He had previously assisted in the executions of murderer Sunny Ang in 1967 and 18 prisoners who had rioted at Pulau Senang in 1965, among others.

"It takes a very brave man to do the job and my granddad had this rare gift which few would have," said Ms Poojaa.

"I have great respect for him and what he did. He saw it as a job which he took seriously.

"He said he was sending the executed to a better place and he had the ability to put them at ease because he was jovial by nature. I believe some even asked for him."

It was this rare ability that moved condemned killers like Ler to bequeath their organs before they were hanged.

"His motto was 'don't worry, be happy', and it showed in the way he carried himself," she added.

Known to be strict with prison inmates, former secret society headmen and fighters detained at Changi Prison feared and respected Mr Singh. They would whisper among themselves "Sar Ji Kau is coming" in Hokkien whenever he reported for work in the jail.

"Sar Ji Kau" referred to the 329 secret society known to be operating in the Rex Cinema area in Little India then, and they nicknamed Mr Singh after the secret society because he was tough and street-savvy.

Ms Poojaa said her grandfather was mentally and spiritually strong to do the job and this was partly because of his personal discipline and lifestyle.

"He would exercise daily, (and his routine) included yoga poses and meditation in the process, which I also learnt. He would eat two raw eggs every morning and it was something he had me do as well - which I hated - but it was necessary for me," she said.

She added that he used to dream of some of the offenders he had executed, such as Mimi Wong, who went to the gallows in 1973 for killing her Japanese lover's wife.

Friend and former colleague Som Datt, 77, who has known him since 1962, said: "Darshan sacrificed a lot, and put his family and friends first.

"He brought up his family on modest means and he was an all-weather friend."

Another long-time friend said: "He deserves the (birthday) party even though he may not fully understand it, and he was moved by the number of people he saw and at times was in tears.

Ms Poojaa said his health is in decline. "But his memories return and his simple maths is still better than mine."

Mr Singh, who has three adopted children and three grandchildren, lives in a Woodlands flat with his wife, Jeleha, and their youngest son, as well as a domestic helper.

Ms Poojaa said he likes a pencil-drawn portrait of himself done more than 40 years ago, which is often mistaken for a photograph.

"It is placed on the wall close to his bed and he would ask me, half-teasingly, 'Who is that handsome man in the picture?'"