The Hong Kong murder suspect Chan Tong-kai was released in Hong Kong on Wednesday after 18 months in custody. It's still unknown whether and when the suspect will surrender to Taiwan.

Chan, 20, is accused of murdering his pregnant girlfriend Poon Hiu-wing, while they were on vacation in Taipei in February 2018. Both of them are Hong Kong residents. Chan later fled to Hong Kong.

This case is believed to have triggered the months-long unrest in Hong Kong.

After Hong Kong announced recently that Chan said in a letter that he would turn himself in to Taiwan authorities, Taiwan initially said it would not allow the entrance of Chan before HK authorities agreed to provide evidence related to this case through legal assistance. And HK responded by asking Taiwan "not to put politics before justice."

There are speculations that Taiwan made this announcement out of the fear that the case may bring uncertainty to its upcoming leadership election.

The night before Chan's release, Taiwan authorities made a surprising U-turn in their attitude, saying they would send officers to HK to escort the suspect to the island. But Hong Kong says Taiwan has no authority to do so and sees this "as cross-jurisdiction law enforcement, which is disrespect for Hong Kong's jurisdictional power and is totally unacceptable."

"Chan will be a free man after being released from jail. The Hong Kong Special Administrative Region (HKSAR) Government has no authority to impose any restrictive measures on him. He could go to Taiwan accompanied by persons of his choice," the HKSAR Government said in a statement on early Wednesday.

Lawyer: HK has no jurisdiction to hear this case 

CGTN asked people in Hong Kong randomly, and most of them believe this case should be heard in Taiwan, but a few think Hong Kong should deal with the issue, as both people involved are Hong Kong residents.

Willy Fu, a member of the Chinese Association of Hong Kong & Macao Studies, told CGTN that it's not possible for Hong Kong to hear this case because the murder occurred in Taiwan.

"HK exercises the territorial jurisdiction, that means all the crime or part of the crime must occur in HK, otherwise the court of HK doesn't have the power to hear the case," Fu explained.

Due to the same reason, Hong Kong can hardly provide evidence to Taiwan, because it probably doesn't have any. 

Urgent need to fill the legal loopholes 

This case reveals a loophole in the legal ground, Fu said, stressing the necessity to improve the existing legal system, to avoid crime refuge. "It's necessary, not only Taiwan but other places to establish mutual legal assistance or extradition agreement with HK, that is a must."

And if Chan changes his mind and does not surrender to Taiwan, the only way that can bring him to justice is mutual legal assistance.

But Fu admitted that it might take a long time to establish such a mechanism, usually one year, but could be longer given the current situation in Hong Kong.