A former president of the Institute of Surveyors on Tuesday said the partial removal of a load-bearing wall at a Tseung Kwan O flat should not be considered completely safe even though the authorities have said there is no immediate risk to the building.

The Buildings Department has ordered the full rebuilding of the wall after the owners of the home in The Capitol at LOHAS Park knocked part of it through to put a new door in.

On an RTHK programme, Vincent Ho said it is right that a temporary framework has been put in place while professionals come up with a permanent solution.

"There are a lot of rebars inside [the wall] and all rebars have to be reconnected where they're cut off," he said.

"So the restoration design requires in-depth study of the current state and how the rebars can be joined together. So professionals like structural engineers are needed to come up with a design for the Buildings Department to examine and approve."

Ho said if nothing was done to remedy the situation, many units above the flat might be affected.

But he told a press briefing later in the day that there should not be any safety hazards once restoration work is completed.

Ho said the incident is just "the tip of an iceberg" as far as potentially dangerous illegal building work is concerned.

He said the Buildings Ordinance puts stringent controls on construction work and owners should make sure that they know and follow the law.

Cheung Chi-tung, former chair of the owners' committee at The Capitol, said more than 300 residents have expressed concern that the incident could affect the safety and value of their flats.

Meanwhile, district councillor Christine Fong said she was in touch with the owners of the flat where the work was carried out and they are upset about the situation, adding that they will be cooperative when it comes to fixing the issue.