Fewer apartments have been put up for sale in Tokyo since flaws were found in hundreds of buildings with falsified construction data, threatening to cut short a rally in home prices.

The number of apartments in Tokyo and surrounding areas that were offered in October dropped 6.5 percent from the same period last year after sales of about 10 properties were postponed until after November, said Tadashi Matsuda, a researcher at the Real Estate Economic Research Institute.

The scandal may derail a rally in the residential market in Tokyo and surrounding areas, where the average price per apartment had been on the rise since late 2011, according to the Real Estate Economic Research Institute. The average price per unit fell to ¥53.6 million ($434,000) last month from ¥59.5 million in July, which was the highest level since at least 2000, the data showed.