SINGAPORE - Two attackers almost got away with brutally slashing a man last August.

But police managed to arrest part-time waiter Peter Nicholas Hamsha, now 22, and Leow Zheng Yang, 21, about two months later, thanks to DNA samples taken from a taxi they had caught to flee the scene.

They attacked businessman Loo Kean Boon, 38, with knives at Club ION at Balmoral Plaza in Bukit Timah Road at around 2am on Aug 10 last year.

The court heard that police were initially unable to establish the slashers' identities as none of the witnesses could identify the pair.

The image resolution of closed-circuit television footage was also too poor to make out who the attackers were. But police managed to trace the taxi later that day and took DNA swabs from it.

The samples were analysed at the Health Sciences Authority and a hit was established with Hamsha's DNA. Police tracked down the two attackers and arrested them on Oct 16 last year.

Hamsha was jailed for 4½ years and ordered to receive six strokes of the cane on Wednesday (July 12), after he pleaded guilty to one count each of causing grievous hurt with a weapon and being a member of an unlawful society.

The case involving Leow, who is jobless, is still pending.

Deputy Public Prosecutor Li Yihong said Hamsha and Leow were members of the same gang.

Some time in the middle of last year, Leow saw Mr Loo at St James Power Station and accused him of being part of a group that beat him up over a staring incident.

Leow decided to seek revenge on Mr Loo even though the latter denied taking part in the attack.

Mr Loo, who runs a pet grooming shop, was in Club ION at around midnight on Aug 10 last year when a member of Leow's gang spotted him.

The gang member alerted Leow, who called Hamsha, and the two men armed themselves with knives before making their way to the club.

DPP Li said: "(Hamsha) snuck up to the unsuspecting victim from behind by crouching down low. (He) then quickly stood up and slashed the victim twice on his head and face, catching the victim completely unawares. (Leow) then joined in and slashed the victim once on his face."

The attackers then ran off, hailed a taxi and fled.

Mr Loo was unconscious when he was rushed to Tan Tock Seng Hospital.

He was found to be suffering from injuries including facial wounds that led to permanent disfiguration, a deep 20cm cut from the back of his head to the right side of his neck and a wound on his right ring finger, with an irreparably damaged nerve.

To try to evade arrest, Leow fled to Johor Baru on Aug 10 last year while Hamsha joined him there the following day.

They returned to Singapore two weeks later when they ran out of money.

After retrieving results of the DNA analysis, police arrested the pair about two months later.

For voluntarily causing grievous hurt with a weapon, Hamsha could have been jailed for up to 10 years and fined or caned.