The authorities have drawn a blank in efforts to deal with a nuisance neighbour who is said to have plagued a Pasir Ris block for more than five years.
Residents of Block 612 at Elias Road claim Mr Liew Chien Siong, 33, is responsible for round-the- clock noise, leaving items dangling dangerously outside his flat and assaulting a neighbour's son.
Two households even plan to move out because of the noise.
Numerous complaints have been made to the Housing Board, Pasir Ris-Punggol Town Council and police - to no avail.
"Even when our MP Teo Chee Hean came, he also refused to open his door," said Mr Ismail Jan, 64, who lives in a unit above Mr Liew's.
He told The Straits Times that Mr Liew, who lives alone on the second storey, bangs on his walls and ceiling at all hours with what sounds like a solid object.
He added: "Police came but said they have no authority to force open the door. I don't know how long I have to suffer this."
All three agencies told The Straits Times they have received complaints but have been unable to contact Mr Liew.
Mr Siew Wen Chang, property manager at the town council, said it "manages only common property" and therefore the HDB and police must deal with the occupant as "the noise is within the flat".
In August, the town council cordoned off an area below the unit after it spotted a blind dangling outside the kitchen window.
Written council notices have gone unheeded. The police say they are working with grassroots leaders and government agencies to address residents' concerns.
The HDB was first alerted to the problem in 2011. A spokesman said: "We have conducted joint inspections with the town council and police. However, each time, there was no response from the occupant. Subsequent visits by the family service centre similarly yielded no response."
After residents complained the block was shaking from Mr Liew banging in his flat, an HDB inspection found it structurally sound.
Its spokesman clarified the HDB has no power to force entry to the unit, but said it will "continue to work with other agencies... to try to reach the occupant to ascertain the source of the noise".
Mr Liew would not answer when The Straits Times knocked on the door at the dimly lit flat last week. It was secured with two rusty padlocks. Banging noises could be heard from it as high up as the 13th storey.
Neighbours said the man does not speak much and is often seen in an army uniform.
Chauffeur Zairi Zaini, 42, said: "It's a matter of time before something serious happens. My family will move out once our new flat (is ready)."
Madam Rafidah, 50, who lives next to the problem unit, also plans to move out, claiming Mr Liew hit her son with a stick in February. Police said they were informed and advised both parties to settle the dispute amicably.