He saw a dramatic arrest at Serangoon Road on Monday.
Mr Alvin Zhang then uploaded an in-vehicle video clip on YouTube, thinking he had witnessed a police raid.
At about 5.45pm, he saw a Comfort taxi being blocked by what he thought were two unmarked police cars and a few motorbikes.
Mr Zhang told citizen journalism site Stomp: "Two plainclothes officers on the bikes quickly got down and smashed the left and right windows of the cab to arrest the suspect."
The arrest was actually conducted by the Central Narcotics Bureau (CNB).
Yesterday, the CNB told The New Paper that the taxi driver was among five Singaporean men arrested by its officers during two anti-drug operations on Monday.
CNB hauled in more than 5.2kg of cannabis, 1.6kg of heroin and 139g of Ice with an estimated street value of more than $316,000 in Monday's operations.
The taxi driver had earlier been tailed by plainclothes CNB officers to a carpark near a housing estate in Geylang Bahru.
A 64-year-old suspected drug trafficker, who had boarded the taxi and alighted shortly after, was arrested and found to be in possession of 239g of heroin.
The 48-year-old taxi driver was later arrested along Serangoon Road.
A CNB spokesman told TNP: "Officers recovered a total of about 1.443kg of heroin and a small amount of 'Ice' from within the taxi. Cash amounting to $2,215.60 was also seized from the suspect."
A 52-year-old man was also arrested when CNB officers raided a unit in Choa Chu Kang North 6, believed to be a hideout used by the taxi driver's associate.
About 82g of Ice, 7g of heroin and a digital weighing scale were seized from the unit.
Mr Zhang's video was uploaded onto YouTube on Monday. Yesterday, it made it to Stomp and attracted more than 38,000 views.
In July 2014, a video clip showing CNB officers arresting a driver who had attempted to evade arrest by crashing his car through the gantry of a public carpark had similarly gone viral.
Footage captured by a witness at a bus stop received more than 132,000 views.
The suspect was arrested along Bukit Batok West Avenue 2 with around 200g of Ice in his car.
But the bigger drug haul on Monday came in a separate raid, when two men in their 40s were arrested at about 4.40pm at a void deck in Sims Drive.
CNB recovered about 170g of cannabis from a 43-year-old suspect. A search of an HDB flat at Sims Drive resulted in the seizure of 5.060kg of cannabis and 139g of Ice.
Under the law, a person can face the death penalty if the amount of pure heroin trafficked exceeds 15g.
A person found guilty of trafficking more than 500g of cannabis may also face the death penalty.
This article was first published on March 18, 2015.
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