NHK has learned that more than 30 percent of the units in high-rise condominium buildings on the Tokyo Summer Olympics athletes' village do not have registered residents.

The site, called Harumi Flag, faces Tokyo Bay in the capital's Chuo Ward.

The Tokyo Metropolitan Government has developed the site into 17 condominium buildings, consisting of 2,690 units, mainly targeting families. Residents have been moving in since January.

NHK earlier reported that companies had purchased some of the units for investment, and many of those units are listed for rent or resale on real estate websites.

NHK has newly discovered that 1,747 units have registered residents as of June 1, while 943 units, which accounts for more than 30 percent of the total, do not. It has not been confirmed whether people reside in those units or not.

Many of the Harumi Flag condos that had shown popularity are believed to be vacant, as the supply of units purchased for investment purposes and being offered for rent or resale exceeds demand.

Meiji University Professor Nozawa Chie is an expert in housing policy. She said that as investors have bought up some units, the condos are becoming out of reach for people who really want to live there.

She added that the Tokyo Metropolitan government should have restricted purchases by investors so that more people can live there and register their residency.