Health minister Lo Chung-mau on Thursday said the hardware of all hospitals needs to be of very high quality, to ensure that patients receive proper treatment.

His comment came after a power outage lasting almost an hour at Kwong Wah Hospital on Wednesday night. The redeveloped building was only completed last year.

Staff carrying out surgery had to move to another room, while 25 other operations were rescheduled.

Lo said there will be a probe into what exactly went wrong.

"The quality of construction works and hardware indeed affects our medical services. The Hospital Authority and the hospital will investigate to find out what the problems were technically," he told reporters.

Medical and health services sector lawmaker David Lam said the problem could be the fault of builders. After the hospital building opened last year, issues with electricity cables were discovered.

"We do not expect a new hospital to have a general power outage problem like that," he told RTHK.

"If that is a systematic problem with the engineering system, or the monitoring system while the building was being constructed, then I believe that's a big issue."