A 45-year-old condominium security guard who was filmed claiming to be a member of the notorious Ang Soon Tong gang was arrested on Tuesday.
Police told The Straits Times yesterday that he was nabbed for being a member of an unlawful society.
Investigations are ongoing.
In a video that was first posted on the Singapore Uncensored Facebook page on Aug 22, the man - wearing a black polo shirt with the word "Security" printed on the back - was seen talking on the phone inside a guardhouse.
Besides uttering several expletives in Tamil and Hokkien, he was heard challenging the other party to "come down to Punggol" to meet him.
The video has attracted over 130,000 views.
The man also claimed to be from Ang Soon Tong, a secret society known to operate in both Malaysia and Singapore. The gang, which has existed since the 1950s, is known for criminal activities such as gun-smuggling, drugs, illegal moneylending and illegal gambling.
Gangster Tan Chor Jin, dubbed the "One-Eyed Dragon", was a member. He was hanged in 2009 after a gangland-style shooting of a nightclub owner in Singapore.
A police spokesman said yesterday: "The police... will come down hard on those who choose to be associated with gangs and their activities." If convicted, the man could be fined up to $5,000 and/or jailed up to three years.