New measures to maintain law and order during the G20 summit in Queensland next year have lawyers concerned people will be locked away in prison without bail.

The G20 Safety and Security Bill, now before State Parliament, would allow police to arrest and detain anyone deemed a threat without giving them bail for at least the week of the summit.

Police would be able to search people on the spot and publicly broadcast the names and photos of people listed "prohibited" from the city.

Peter Shields from the Queensland Law Society says the proposed changes are drastic and a breach of basic rights.

"It is a bill which has not been properly thought through, and there are going to be innocent members of the public who will find themselves in custody," he said.

Criminal lawyer Bill Potts says for the period of the summit, the normal rights that citizens expect will be "suspended and abrogated in the most draconian way".

"The legislation for example makes it an offence to be in possession of prohibited items," he said.

"That can include eggs, cans of baked beans, model cars, model aircraft and all sorts of things which may be used as projectiles even though they have a simple and ordinary use."

Eggs, reptiles, surfboards and other items banned

As well as obvious weapons, many other items are prohibited in the secure zone including glass bottles or jars, reptiles, metal cans or tins, hand tools, handcuffs, surf-skis or surfboards and banners bigger than 1m x 2m.

Police will also be allowed to publish the names and photographs of anyone they decide should be prohibited from entering the secured inner-city zone.

At Toronto's G20 riots in 2010, more than 1,000 people were arrested.

Mr Potts says south-east Queensland's watchhouses cannot handle even half of that.

"We have a small watchhouse in Brisbane. We don't have sufficient resources," he said.

"So I've got no idea, nor does the (Law) Society, where the Government intends to house those persons who are remanded in custody."

The Law Society and Queensland Police Service will hand their submissions to the committee this week.

In a statement, committee chairman Ian Berry says "the committee has yet to give the bill any detailed consideration and the committee has not formed any views on the bill, as yet."

The bill is due for debate by the end of October.

The powers could come into effect in Cairns from the third week of next February.

Tens of thousands of homes and businesses in Brisbane will be enclosed inside the security perimeter during mid-November next year.