Immigration director-general Sakib Kusmi says he is empowered by the law to decide whether or not government critics can leave the country.

Thus, he said, the ban list was based on his own discretion, as well as the advice of other enforcement agencies.

"For example, if the police say someone is dangerous, even though it (the matter) has not gone to court yet, we can take action," he said when met at the Kuala Lumpur International Airport today.

He was commenting further on his previous remarks that critics of the government would not be allowed to leave the country.

Section 3(2) of the Immigration Act, states that the "director-general shall have the general supervision and direction of all matters relating to immigration throughout Malaysia".

The act also states that the immigration chief is given powers to bar entry into Malaysia, but there is no specific provision on leaving the country.

Sakib defended the barring of critics as a preventive measure.

"We don't want to act only after something happens," he said without elaborating.

He also said there was a difference between criticising the government and insulting it.

"As long you have no intention to be radical, there's no problem... You can criticise, but it must be positive criticism.

"Not criticism saying this person is no good. Some don't even criticise but insult, that is worse."

However, he denied that this was politicking.

The issue of government critics being barred from leaving the country came to light after Bersih chairperson Maria Chin Abdullah was denied exit.

Deputy Home Minister Nur Jazlan Mohamad, however, has said this ban only applied to those who violated the Federal Constitution, for example by being seditious or stoking racial hatred.