An unofficial protest song played as the Hong Kong team lined up for the men's final of the Asia Rugby Sevens Series in Incheon, South Korea on Sunday.
Hong Kong CNN  — 

The Hong Kong government on Monday demanded an investigation after a song associated with the city’s pro-democracy movement was played instead of the Chinese national anthem before a rugby sevens match between Hong Kong and South Korea.

Event organizers played an instrumental version of “Glory to Hong Kong” as the teams lined up for the men’s final of the Asia Rugby Sevens Series in Incheon, South Korea on Sunday. The song, an unofficial anthem of the city’s 2019 pro-democracy protests, includes lyrics that a Hong Kong court has previously ruled could incite secession – a national security offense.

Clips of the incident, in which the team is shown standing to attention on the field as the song plays, circulated widely on social media Monday, threatening to overshadow Hong Kong’s 19-12 victory.

In a statement, the Hong Kong government said it “strongly deplores and opposes” the playing of the song, which it said was “closely associated with violent protests and the ‘independence’ movement in 2019.”

“We have already written to the Hong Kong Rugby Union last evening demanding them to deal with this matter seriously, launch a full and in-depth investigation and submit a detailed report, and convey our strong objection to Asia Rugby, who is the organizer of the Series,” a government spokesperson said, according to the statement.

In a statement Monday, Asia Rugby apologized for the incident, saying it “happened due to a simple human error from a junior member of the local organising committee, playing a song downloaded from the internet instead of the correct anthem.”

The match’s local organizer, Korea Rugby Union (KRU), told CNN the mistake occurred when a worker searched online for a Hong Kong anthem and added the top result to a folder labeled “Hong Kong.” The broadcasting room staff played the music file in the Hong Kong folder instead of one labeled “China,” the organization said.

The organizer apologized through the stadium speaker and played the Chinese national anthem at the end of the match, according to KRU.

“Korea Rugby Union will take all measures to prevent a repeat of such an occurrence in future matches,” the organization said, adding that its “Hong Kong” folder has now been erased.

In a statement, the Hong Kong Rugby Union (HKRU) said it “expressed its extreme dissatisfaction” over the incident to the organizers. “Whilst we accept this was a case of human error it was nevertheless not acceptable,” the statement said.

Last week, a woman who waved a British colonial-era flag to celebrate Hong Kong claiming Olympic gold became the first person in the city to be jailed on a charge of insulting the Chinese national anthem.

Hong Kong, a former British colony handed over to Beijing’s rule in 1997, sends its own representative teams separate from mainland China to a wide range of sporting events, including the Olympics.