Resale prices for Housing Board resale flats fell 1.2 percent in May from the month before, marking the fourth consecutive month of decline and hitting a two-year low. The Singapore Real Estate Exchange's HDB price index hit the lowest level since April 2012, according to flash figures on Thursday.

This was on the back of price declines for all HDB flat types. Prices of three-, four-, five-room and executive flats fell by 0.8 per cent, 0.8 per cent, 0.6 per cent and 2.8 per cent respectively.

Prices have declined by 6.5 per cent since their peak in April 2013 and 2.7 per cent since the start of the year.

Resale volumes were also down 11.1 per cent, contrary to experts' expectations of a recovery in transactions. There were 1,320 flats sold in May compared to 1,484 in April. This was also 19.4 per cent less than the 1,637 sold in May 2013.

In the HDB rental market, volumes edged up but prices stayed roughly flat. An estimated 1,564 flats were rented in May, up 1 per cent from April. Rental prices were down by a marginal 0.3 per cent.

According to SRX's median Transaction Over X-Value measure, the amount that buyers are underpaying for their flats remained stable at $4,000 below SRX's estimated market value.