While the bulk of cases under the new security law will be handled by local authorities, suspects in some cases will be tried on the mainland courts under the law there.
The mainland security agents can assume control of cases under the new legislation in three specific circumstances.
These include when cases involve 'complicated situations' where there's foreign interference and the SAR government has difficulties exercising its jurisdiction; when the local government cannot effectively enforce the law; and when there's a serious threat to national security.
Either the Office for Safeguarding National Security of the Central People's Government (CPG) in the HKSAR or the government should first request permission from Beijing for the mainland agency to assume control of the case.
Suspects involved in these cases would then be tried in a mainland court, under mainland law.
However, the legislation did not specify whether the death penalty, which is applicable under mainland law for national security offences, could be applied in such cases.
Under the new legislation, the maximum penalty is life imprisonment.
The convenor of the pan-democratic camp in Legco, Tanya Chan, said "there is a very large possibility that if a Hong Kong person as a defendant is going to be sent to [the mainland] for trial, the maximum penalty may be the death penalty.”
"I urge the government to explain to the public the implementation of this law in both Hong Kong and China, and also how our government is going to protect our rights and freedoms of Hong Kong people during trial in both Hong Kong and China”, she added.
The law also says suspects tried on the mainland will be allowed to hire a lawyer and "have a right to receive a fair trial as soon as possible".
A government statement also said the law will not have a retrospective effect.
"It has no retrospective effect and the stipulated offences are only applicable to acts after the commencement of the law," the statement said.