A Legco subcommittee completed the vetting of subsidiary national security laws on Thursday, after spending more than five hours examining the provisions clause by clause.

The subcommittee was formed during a special House Committee meeting in the morning to scrutinise the new subsidiary laws by negative vetting.

Subcommittee chairman Martin Liao said he'll report its work to the House Committee on Friday.

Liao was among the same group of 15 lawmakers on the subcommittee who vetted the national security bill under Article 23 of the Basic Law last year.

No one present at Thursday's meetings said they planned to move any amendments.

Secretary for Justice Paul Lam thanked the subcommittee for its work.

The minister said the efficiency showed that the executive and legislature had worked together to fulfil their constitutional duties to safeguard national security by improving relevant laws.

"We have spent more than five hours, and the number of questions plus opinions expressed by members of the Legislative Council exceeded 150," Lam told reporters.

"So I think any reasonable person would have agreed that the whole process is extremely serious, and that thorough discussion had been given to all relevant provisions."

Lawmaker Regina Ip, who was on the subcommittee, said she too was satisfied with its work.

"We actually exceeded the time allowed for us to do the scrutiny. Two meetings were provided for, but we actually ran three sessions, running into more than five hours and we raised more than 150 questions.

"I think all of us discharged our duties very vigorously and very conscientiously, and I'm satisfied that the legislative procedure is a completely satisfactory one."

Security minister Chris Tang stressed that the government will keep improving security laws if necessary.