The inquiry was due to take evidence at a hearing in Hobart on Friday but those giving evidence were told on Thursday the hearing had been cancelled.

Gun Control Australia vice chair Roland Browne, who was due to give evidence, was reluctant to comment on the suspension.

“I was due to appear but I was told it had been cancelled,” Mr Browne said.

“I emailed asking for an explanation but have had no reply.”

The House of Assembly committee inquiring into Tasmania’s gun laws has been left one member short with the resignation from Parliament this week of Liberal member for Braddon Adam Brooks.

It had already held two hearings last year - without Mr Brooks who was on sick leave.

A government spokesman said: “It is a matter for the committee whether its work proceeds following the resignation of Mr Brooks.”

“The current Terms of Reference for the committee do not provide for substitute Government members, so it will be a matter for the House of Assembly to appoint a replacement Government member when it sits next month.”

The inquiry was due to report to Parliament by March 14.

More on the Legislative Council firearms inquiry:

Greens leader Cassy O’Connor said it was hard to see how the postponement “won’t set the committee back well past the deadline”.

"It is disappointing that two days of public hearings have been postponed, given the significant public interest in community safety," Ms O'Connor said.

"The Government must explain to those witnesses set to appear why they are cancelling the hearing of their evidence.

"If it is because Mr Brooks has resigned, it’s hard to understand why this is a valid reason given the public hearings held by the Committee have already been occurring in his absence anyway."

Ms O'Connor said committee chair Mark Shelton should explain why the hearing was suspended.

Police Minister Michael Ferguson said the government had moved to establish the committee and looked forward to it finalising its inqury.

"The conduct of the inquiry is a matter for the Parliamentary Committee, and the members of the committee have resolved to resume the inquiry again when it has full membership addressed," Mr Ferguson said.

"The government’s position is that our firearms laws are among the toughest in the world and that is how they should remain.

"Our overriding principle in relation to any proposed changes continues to be that we will not do anything to undermine the National Firearms Agreement."

Tasmania Police, White Ribbon Australia, the nurses union, Legal Aid Commission and Tasmanian Conservation Trust were all listed to give evidence at Friday's hearing.

Last week Gun Control Australia won a court case over the government's denial to provide a Right to Information request about gun law changes proposed prior to the March state election.