Sales of units in a pair of high-rise condominiums in the Tokyo Bay area have been suspended due to the possibility that the concrete used to build them was substandard.

The twin skyscrapers, each 189 meters tall with 53 floors, were being built in the Toyomi district of Tokyo's Chuo Ward.

Construction of the skyscrapers began in January last year to replace an old housing complex. They were due to be completed in 2026.

But tests carried out on samples of concrete showed that some had strength below standard. The examinations were conducted by Shimizu Corporation, which designed and has been building the condominiums.

The company plans to examine the test results in detail.

It says it will engage in discussions with relevant parties to understand why this happened and determine the necessary actions.

The real estate developer, Mitsui Fudosan Residential, decided to indefinitely suspend sales of the condominiums' units, which were to begin later this month.