Notorious sex offender Robert Fardon is likely to breach strict supervision orders and strike again if he's released from jail, a Brisbane court has been told.

Queensland's attorney-general has sought a stay on an order to release the 64-year-old.

Supreme Court Justice Peter Lyons last week ruled Fardon should be freed from his indefinite jail term, but under strict supervision.

He conceded there was a risk Fardon would breach the conditions of his supervision order, but it was unlikely any breach would go undetected for long.

"That in turn makes it unlikely that Mr Fardon would progress to committing a sexual offence," Justice Lyons found.

But lawyers for the attorney-general challenged that view in a hearing on Friday.

"It's likely the supervision order will be breached. In that case adequate community protection can't be assured," barrister Jonathan Horton told the court.

"On the basis of his past conduct one must be seriously concerned about the (possible) commission of offences."

Fardon's lawyer Dan O'Gorman QC pointed to Justice Lyons' view that his client presented a manageable risk.

"They (any offence by Fardon) are likely to be detected before they are committed," he said.

He also criticised lawyers for the attorney-general, saying they had only notified him of their grounds for appeal half an hour before the hearing started.

"We were advised the attorney-general was likely to take this stunt, sorry, I mean this step," he said.

The hearing continues.