The Hong Kong International airport is under scrutiny following its decision to allow screening of carry-on bags without the presence of owners. While many do not seem to allow it, the city government insists that it is by international standards.

According to South China Morning Post, local officials stated that the procedure mentioned above falls under international standards. However, airports in London, Munich, and Singapore, passengers should be present when their bags are being screened. It is a necessary step before they can enter the restricted area.

If passengers realize that they left a carry-on bag on the other side and the security check is already done, they will have to go out. After retrieving, they will have to undergo the same security check again. As far as the US Transportation Security Administration (TSA) is concerned, the Hong Kong airport must do the same. TSA is responsible for overseeing security at all US airports.

The question of whether passengers need to be with their bags for screening came up after the High Court ruled that Hong Kong International Airport bosses broke security rules in March 2016 when dealing with then chief executive Leung Chun-ying's daughter.

Leung Chung-yan had already cleared security and was bound to take a Cathay Pacific Airways flight. However, she realized that her other bag was misplaced. After her father called the airline for help, airport staff found the bag outside the restricted area and took it through security before delivering it to her at the gate.

In his ruling last week at the end of a judicial review, Yahoo! News reports justice Anderson Chow Ka-ming declared that the Aviation Authority and the Aviation Security Company (Avseco) had broken the rules in force at the time, which said the passenger had to take their bags through screening.

The rule has since been alleviated to enable checking of cabin bags in the owner's absence, despite airlines and airports globally implementing tighter screening rules for carry-on luggage.

Several days later, Secretary for Security John Lee Ka-chiu said: "Our existing aviation security procedures are similar to those exercised at international airports in various countries."

For aviation security expert Chris Bala, the managing director of Singapore-based CJ Security Consulting, airports usually require passengers to be present while their cabin bags are screened.

He said that the main reason behind it is for the passenger to be asked immediately to open the bag if there are any irregularities.