The mother and son hoard so much that piles of rubbish have overflowed from their 20th-storey flat into another unit two storeys below.
The other flat, which belongs to the woman's mother-in-law, also became packed with rubbish from floor to ceiling.
Their neighbours in Block 222, Toa Payoh Lorong 8 call the hoarders "terrors" because of their aggressive behaviour. They shout at people just for looking at them.
On Monday, they lived up to that name when the authorities went to the four-room flat of the mother-in-law, a frail 91-year-old woman known only as Madam Tan, and they refused to let them remove the hoarded items.
The mother, 55, and her son, 20, created such a scene, shouting and gesticulating loudly, that the police arrested them and took them away in a police car.
The New Paper understands that they were later released on bail.
Cleaners from the town council then moved in to clear the rubbish from Madam Tan's flat.
They were there from 11am to 3pm but could clear only part of the living room.
When TNP went to the block yesterday, the authorities were there as the cleaners continued clearing Madam Tan's unit.
The area's MP, Mr Sitoh Yih Pin, told TNP that he had initiated the joint operation that was coordinated by the HDB and involved the National Environment Agency (NEA), the Potong Pasir Town Council and the police.
Mr Sitoh said: "I received a lot of complaints from the residents about how things are stashed in the flat... it was a safety hazard."
A neighbour, who gave her name only as Nicole, described her life as a "living hell" ever since the hoarding started almost 10 years ago.
"My life has been a daily war with cockroaches that crawl around the outside of their flat every day," said the 21-year-old, who is unemployed.
"Whenever I come out of the lift and walk past their flat, I get very scared of the cockroaches."
She also keeps her windows closed as the pests often try to enter her unit.
"Even with the windows closed, I spray insecticide every month," she said.
"Sometimes I hear a sound at the window and think that someone had dropped something. But it's often a cockroach flying smack into my window panes."
Nicole also said that the family often made a din late into the night, raising their voices and causing a disturbance to the neighbours. "Even at midnight, they would shout in Hokkien till about 1am," she said. "My life has been a living hell."