The 44-year-old who kidnapped the elderly mother of the Sheng Siong supermarket boss and demanded a ransom of $20 million has been sentenced to life imprisonment and three strokes of the cane, after the High Court turned down his plea for the death penalty.

In a letter to the court, Lee Sze Yong sought the victim's forgiveness for kidnapping her in 2014 and asked to be sentenced to death as he could not bear the thought of "hopeless years ahead" if he was to spend the rest of his life behind bars. "I had ruined my life. By dying, I hope that I have repaid my debt and to be at peace," he wrote.

Both his lawyer and prosecutors had submitted that Lee should get a life term and three strokes of the cane.

In sentencing Lee, Justice Chan Seng Onn advised him not to despair as the law allows a review of life sentences after a prisoner has served 20 years. "There is still hope at the end of the day," said the judge, adding that he could still turn over a new leaf. "I understand, Your Honour," Lee replied.

Contacted by The Straits Times, Sheng Siong chief executive Lim Hock Chee said he had no comment on the sentence.

"I would like to thank the public for their concern and the police for their help," he said in Mandarin.

Mr Lim added that his mother, Madam Ng Lye Poh, now 81, cannot walk long distances as her legs are weaker now, but is "generally okay".

Lee's sentence was backdated to Jan 9, 2014, the day the sales executive was arrested for abducting Madam Ng, who was then 79, and demanding a $20 million ransom from her son.

In his trial earlier this year, Lee admitted he had harboured plans for years to kidnap the rich in Singapore to clear his debts, which had ballooned to about $200,000. His first target was the children of billionaire investor Peter Lim.

In 2013, he started staking out the Hougang house of the Sheng Siong boss and decided to target Madam Ng after observing her movements.

On the morning of Jan 8, 2014, he approached her at an overhead bridge and asked her in Hokkien if Mr Lim was her son.

After she confirmed that he was, he tricked her into getting into his rented Honda Civic by lying that her son had a fall in the office. She was blindfolded and driven around for 12 hours. Lee phoned Mr Lim and demanded $20 million, but the sum was negotiated down to $2 million.

Madam Ng was released after Mr Lim dropped off a bag with the cash in Sembawang Park.

Lee was arrested in Ang Mo Kio shortly after and led police to the bag and cash, which he had thrown into some bushes at the same park.

While Lee admitted his actions, he disputed the mental element of the offence. He maintained that he would have released the elderly woman that night even if he did not receive the ransom.

His lawyer, Mr Selva K. Naidu, had argued that Lee was not guilty under the Kidnapping Act as his intention was not to hold the victim until the ransom was paid.

Justice Chan rejected this contention, saying that the defence's interpretation of the law was "unduly restrictive" and "untenable".

During his trial, Lee also admitted that by threatening to expose his relationship with former sexual partner Heng Chen Boon, he got Mr Heng to help him swop cars and guard the victim.

Mr Heng, 52, has served a three- year jail term on a reduced charge of helping Lee abduct Madam Ng.

There have been only three confirmed cases of kidnapping for ransom in the past 10 years, and all perpetrators were arrested and later jailed for life, police said.

Video

What Lee Sze Yong wrote in the letter http://str.sg/4QX3