Court apologises for barring reporter

The Federal Court has apologised to a journalist who was barred from a public hearing into Australia's free trade deal with China.

A Brisbane court security guard refused entry to an AAP reporter trying to attend the Senate Joint Standing Committee on Treaties hearing on Monday afternoon.

There was a large union protest, opposing the trade deal, outside the building at the time.

The security officer told the reporter only the public and not journalists were allowed inside.

But the Commonwealth Law Courts did not approve her decision and says the hearing was supposed to be an open event.

"This was done without referral to the Federal Court," a spokesman told AAP.

"It is regrettable that this happened and steps have already been taken to ensure it doesn't happen again."

Committee chair Wyatt Roy told AAP he was "absolutely" disappointed the journalist had been turned away from the public hearing.

After barring the reporter, the court security guard proceeded to escort members of the public in and out of the building.

A female police officer standing nearby at the time suggested that as committee proceedings were already under way, entering the "very small" hearing room could be disruptive.