The vice president of Sumitomo Mitsui Construction, the prime contractor for the tilting condominium building in Yokohama, has apologized over the incident — the first such acknowledgment of regret by the company since the scandal broke mid-October.

"We deeply apologize for causing troubles and worries," Yoshio Nagamoto said during a news conference in Tokyo Wednesday to announce the company's midyear earnings results.

"We accept the grave responsibility as the prime contractor. We weren't thorough enough. We should've supervised better."