The student who dressed up as a "killer clown" has apologised for his actions, admitting that the prank had "backfired" after he received negative feedback on social media.

In a six-minute video posted on YouTube on Monday night, Mr Joel Wong said he had taken both videos of the prank, which showed the 19-year-old, dressed in white and wearing a clown mask, trying to scare passers-by at a park and an underpass.

Mr Wong claimed he had been hauled up for questioning by the police, who showed up at his home on Monday.

The friends who had assisted in the prank were also taken in for questioning, he added.

"We filmed the video extremely impromptu. I guess I just rushed into it and really did not consider the consequences.

"I was careful with how I executed the prank in the sense that I made sure no real (or fake) weapons or harmful objects were used, and that I kept a good distance from the people I scared," he said.

"Of course, I missed the whole big picture - that I was still in fact scaring innocent people and causing a public nuisance... I wanted to make a viral video. I guess that was the only thing that I managed (but in all the wrong ways)."

The original video of the prank, put up on Sunday, was criticised by netizens. Mr Wong later uploaded another video which contained behind-the-scenes footage of the prank, revealed to have taken place over three days last week.

He had intended to hide in a big box and jump out to scare people on the final day, Saturday, but his plans were scuppered by heavy rain. That was when police officers, responding to a call for help at Block 489C, Tampines Street 45, at 10.40pm, turned up and spoke to Mr Wong.

The Straits Times understands that investigations are ongoing.