A 26-year-old man was found dead outside a unit on the sixth floor at Block 279 Yishun Street 22 on Saturday (Jul 9).
A 20-year-old male suspect was arrested in connection to the case, said the police.
The police were first alerted at 7.57pm requesting for assistance, and paramedics pronounced the man dead at 8.29pm. Police investigations are ongoing.
Channel NewsAsia understands that both men had been involved in a prior dispute, and that no weapon was used in the incident.
According to Mr Diin, 42, who lives on the fifth floor, he heard a "loud bang" at 7.45pm, but added that he did not know what happened exactly.
"I heard a very loud thumping sound. It's like something dropped onto the floor. It's a very loud sound. I thought my neighbour was moving something," Mr Diin recounted.
Mdm Tan Saik Khar, 75, who lives on the sixth floor, claimed that she had been attacked by the 26-year-old man on Wednesday night. She said he ran away after she shouted for help.
Another neighbour, Andy, 37, also said that he had started noticing the man two years ago, as he would loiter at the void deck up to four times a week. “He has never spoken to me before, but he would just stare at me and walk around the block for a few hours,” he said.
Earlier the same day, the body of a 52-year-old man was found at Geylang Lorong 23. Police said they were investigating the "unnatural death".