A board of inquiry would have broad powers, including the power to subpoena witnesses and documents, to help get to the bottom of the crisis which now looks set to end in the demolition of up to 1000 homes across the city at a cost of hundreds of millions of dollars.

"The families who are affected and the ACT taxpayers need to know what went wrong over a protracted period that has led to thousands of people potentially being exposed to loose-fill asbestos and potentially the ACT taxpayer being out of pocket by hundreds of millions of dollars," he said.

"I can think of few more significant issues in the Territory's history that would have had such an impact on ACT residents and on the ACT budget, and I think we need to learn the lessons so that it never happens again."

An inquiry would look at why the ACT Government allowed the homes to be extensively renovated and extended, and to be sold and resold, sometimes many times over, despite repeated advice in internal reports that the issue should have a much higher profile - with far greater awareness among home owners, and stronger protections for buyers, renters and tradespeople.

It was not until this year, after the extent of contamination was uncovered during the demolition of a Downer house last year, that those protections were put in place.

It could also look at why the company colloquially known as Mr Fluffy was allowed to pump dangerous loose-fill asbestos into the ceilings of more than 1000 Canberra homes over 11 years from 1968 to 1979 despite warnings only months into his operation that he should be stopped in his tracks because of the health risks.

Chief Minister Katy Gallagher has said she didn't take stronger action previously because the seriousness of the contamination and risks was not known until the Downer demolition last year.

But it is clear from several documents, revealed by The Canberra Times on Thursday, that the government was also concerned not to damage people's property values. It bowed to pressure from homeowners concerned about values when it worded a letter to residents in 1993, and more recently cited house values as one of the reasons for refusing a freedom of information request for the list of Mr Fluffy homes; privacy was another key concern.

Mr Hanson said he had spoken to Ms Gallagher and federal Employment Minister Eric Abetz about his call on Thursday for an inquiry, and told both of them he did not want it to derail or delay a decision on the future of the 1000 homes, which was the first priority. The inquiry should only begin once that decision - which is imminent - had been made, Mr Hanson said.

An inquiry would be set up by the Government, so would need Ms Gallagher's agreement. The alternative is for the ACT Assembly to vote to force the Government to set up an inquiry, but the Government controls numbers in the Assembly.

It would be independent of government, presided over by the likes of a former judge, and set up under the Inquiries ACT 1991.

Mr Hanson said it should be comprehensive and detailed.

Mr Hanson has offered bipartisan support to Ms Gallagher on resolving the asbestos issue, and said on Thursday that he remained committed to supporting the government in reaching a solution. Once a decision was made, the inquiry would "look at what on earth has done wrong for such a protracted period".

A board of inquiry has broad powers, with the right to "inform itself of anything in the way it considers appropriate", and to "do whatever it considers necessary or convenient for the fair and prompt conduct of the inquiry", according to the Inquiries Act.

It has the power to subpoena witnesses to give evidence under oath, to access documents, and to use search warrants. Members of a board of inquiry have the same protection as a judge of the Supreme Court. Lawyers assisting and people subpoenaed have similar protections. And contempt rules operate similarly to the courts.

Hearings are in public unless the board decides to hold private hearings to deal with confidential information.