A teenager went to a supermarket amid the Covid-19 outbreak in early February and took two bottles of fruit juice from a refrigerated shelf.
Nigel Pang, 18, then sampled both drinks before replacing them on the shelf.
Quek Xuan Zhi, 17, recorded his friend's antics and posted the video on Instagram, via an Instastory, with the caption "How to spread Wuhan virus".
Wuhan, a city in China, was the epicentre of the Covid-19 outbreak at the time.
In an earlier statement, the police said an acquaintance recorded a copy of the video and circulated it online. This caused public alarm and concern.
The two Singaporean teenagers each pleaded guilty yesterday to one count of being a public nuisance.
Around 6.45pm on Feb 6, they had gone to a FairPrice outlet in Bukit Batok West Avenue 7 and Pang helped himself to the drinks. Quek posted the video on Instagram using an account that had more than 1,300 followers at the time.
Deputy Public Prosecutor Timotheus Koh said: "Pang later paid for the two bottles of juice that he drank from. Pang knew that Quek would caption the video 'how to spread Wuhan virus' and post it on Instagram.
"Pang told Quek to highlight... that he had paid for the bottles of fruit juice, but Quek posted this information in a subsequent Instastory instead."
The DPP said the video later gained traction on social media, with many members of the public expressing annoyance with the teenagers' antics.
A 21-year-old woman who came across the clip alerted the police on Feb 8.
On Thursday, DPP Koh said that due to the offenders' youth, rehabilitation is "at the forefront" in this case.
Deputy Principal District Judge Seah Chi-Ling then called for reports to assess their suitability for probation.
The teenagers, who are out on bail of $3,000 each, will be sentenced on Aug 27.
For being a public nuisance, an offender can be jailed for up to three months and fined up to $2,000.
This article was first published in The New Paper. Permission required for reproduction.
