Chief Executive John Lee made it clear on Tuesday the police would investigate the anthem mistake at the Asian Rugby Sevens Series in South Korea over the weekend.

He reiterated it's unacceptable that a song associated with violent protests in 2019, instead of the national anthem, was played.

Speaking to the media before the weekly Executive Council meeting, Lee did not elaborate on how the probe will be conducted or whether officers will travel to South Korea to collect evidence.

He was asked what could be done to prevent similar incidents in future.

“It is the responsibility of the organisers. We’ll do our best to assist the organisers to fulfil their obligations. But it is important that when mistakes are made, when problems arise, we point those problems out and there is a good investigation to know what actually happened, so that we will deal with the situation accordingly,” he said.

Exco convenor Regina Ip told a radio programme that the Hong Kong police have the responsibility to look into the matter.

She said she didn’t believe it was a careless mistake, adding that officers should look into whether someone from Hong Kong had conspired with people there to conduct seditious or subversive acts.

“Hong Kong and South Korea have mutual legal assistance agreements. We have signed it long ago, it’s our law. We have undertaken to help each other. Hong Kong police should act in accordance with this agreement and ask for South Korea’s assistance,” she said.

Ip noted that Hong Kong’s national security law asserts jurisdiction outside the SAR, and if people from South Korea are believed to have engaged in criminal acts, Hong Kong can request Seoul to extradite its nationals to face trial here.

The event organiser, Asia Rugby, has offered an apology, saying it was the result of human error by a junior staff member.