In a move that lawyers said reflected the intense public interest in the case, police have arrested a couple, believed to be the ones seen quarrelling with an older man in a hawker centre, for causing public nuisance.
A video clip of the incident had been posted online, sparking negative reactions.
In a statement, police said officers arrested a 46-year-old man and a 39-year-old woman on Tuesday. They had allegedly used offensive language and force against a 76-year-old man at a hawker centre in Toa Payoh Lorong 8.
Police received reports about the case on Sunday and the couple's identities were established through follow-up investigations.
Investigations are still ongoing.
Lawyers told The Straits Times yesterday that arrests for causing public nuisance are not common.
Mr Raphael Louis from Ray Louis Law said officers could have arrested the couple because the case had attracted a lot of public attention - most of it negative.
"Moreover, the case was between a relatively young couple and an elderly man, who is a vulnerable victim," he added.
Another lawyer, Mr Rajan Supramaniam from Hilborne Law, shared his view. He said: "Causing public nuisance is not a serious offence. However, there has been a lot of public interest in this case and so a warrant was issued for the couple to be arrested after the police conducted their investigation."
Mr Supramaniam said a person convicted of causing public nuisance has performed an act that has annoyed the public or disrupted the public peace. This includes using vulgar language and shouting in public.
Mr Louis said the police will likely consult the Attorney-General's Chambers, which will then decide if the couple should be charged in court.
The online video, lasting a minute or so, showed a woman and an elderly man exchanging words over a table at the hawker centre.
Her companion is later seen walking into the scene and, as he does so, knocking into the older man, who falls against the tabletop.
A woman claiming to be the old man's daughter has hit out at the couple's treatment of her father.
In a Facebook post on Tuesday morning, Ms Caroline Ng said she learnt about the April 21 incident after reading several online posts and watching a video of it.
She wrote: "No words can express my outrage and disgust... What I find unbelievable is for the entire two days, my dad never for once mentioned a word of it."
Those convicted of being a public nuisance can be fined up to $1,000.
WARNING: STRONG LANGUAGE