The advertisement was picked up by the media and caused an uproar. The real estate agent who handled the HDB flat told the media that the HDB flat belonged to a couple who bought a landed home as the family's business was getting better, so the HDB flat was left unoccupied for a long time.

This answer probably made the netizens waiting in line for the HDB flats even more angry, with many of them exclaiming "These people need HDB flats!" In response to the heated debate on the internet, the Singapore government had to step in.

In response to questions from netizens, Minister for National Development Lee Chee Seng recently took to Facebook to answer the question, "This is not acceptable.

The owner of a pre-purchased HDB flat must occupy the flat during the MOP (Minimum Occupation Period) and if the owner is unable to meet the MOP, the flat will have to be returned to HDB.

The HDB will then classify the flat as a surplus HDB flat for other buyers to apply for.

Otherwise, the homeowner is considered to be in breach of HDB regulations and the authorities will initiate an investigation accordingly."

Under Singapore law, homeowners are required to meet a five-year minimum residence period before they can resell their HDB flats, or 10 years for prime HDB flats, after purchasing them.

The minimum residence period is counted from the time the owner receives the keys, and if the owner does not live in the HDB flat in the interim for special reasons, this period does not count towards the minimum residence period.

Owners who contravene this law may be subject to compulsory repossession and face a fine of up to $50,000 or a written warning. The repossessed flat will be sold as a surplus HDB flat and the owner will not be able to purchase a subsidised HDB flat or apply for a rental HDB flat for the next five years.

In a recent interview with the media, HDB also said that it would be keeping a close eye on news of illegal HDB flats for sale on the internet and, of course, on the Yishun HDB flat that has been the subject of much discussion recently.