The man behind Queensland's historic corruption inquiry, Tony Fitzgerald, has delivered a scathing verdict of the Newman Government's new laws targeting bikies and sex offenders.

Queensland recently introduced some of the toughest anti-bikie laws in the country, restricting members' and associates' movements and meetings, and increasing minimum sentences for their crimes.

Under the changes to the state's sex offender laws, the Attorney-General will have the power to keep serious sex offenders in prison indefinitely, taking away that role from the courts.

Judges, lawyers and civil libertarians have all voiced concerns about the changes, but Premier Campbell Newman has labelled critics as "apologists for paedophiles".

Now, the man who presided over the judicial inquiry into Queensland police corruption in the late 1980s, and which brought about the end of former Queensland premier Joh Bjelke-Petersen's era, has added his voice to the debate.

In recent years Mr Fitzgerald has been a man of few words, but in an opinion piece for the Courier-Mail newspaper, he slams the new laws.

Mr Fitzgerald warns it is "foolhardy" for politicians to make major changes to the criminal law without consulting legal experts.

"Although Parliament has power to enact almost any law which it chooses, parliamentarians who are elected to do what's best for the community don't have a mandate to give effect to prejudices and ill-informed opinions, ignore ethics and conventions or attack fundamental values such as personal freedom or essential institutions such as the judiciary," he writes.

Mr Fitzgerald says it is "extremely arrogant" to denigrate the judiciary and slander those who disagree with what he calls the Government's "political solution".

He adds that any Queenslander "who is even remotely aware of the state's history" should be wary of a government interfering with the criminal justice system.

"History teaches us that claims that repressive laws will reduce serious crime are usually hollow and that laws which erode individual freedom and expand a state's power over its citizens are fraught with peril," he writes.

"Although free societies provide opportunities which criminals can exploit, in totalitarian states the worst criminals are commonly those in power."

Mr Fitzgerald says there is an uncomfortable similarity between what is happening in Queensland and demagogues, who are described as political leaders who appeal to the emotions, fears and ignorance of less-educated voters to gain power and promote their own motives.

Queensland Attorney-General Jarrod Bleijie has dismissed the criticism.

"Mr Fitzgerald is entitled to his opinion ... that's the great democracy we live in," he said.

"We're getting on with the job, we're doing what Queenslanders elected us to do 18 months ago and that's to restore the balance of justice in Queensland and get the balance of scales right.

"Two-strike sex offender laws, serious assaults on police officers, graffiti offences, youth justice offences - the new criminal motorcycle gang laws and the sex offender laws are an extension to those already tough laws."