At least 30 Canberra homes subject to checks in recent weeks have been confirmed to contain residual Mr Fluffy asbestos - including one house with fibres on top of its fridge.

Canberra's largest asbestos assessment firm, Robson Environmental, has checked 30 houses - with 25 testing positive for the deadly loose amosite fibres in their wall cavities or subfloors.

Another experienced local asbestos assessor, Frank Poole, said that all five houses he inspected had come back positive for residual Mr Fluffy.

Licensed asbestos experts have been run off their feet in the weeks since the ACT government sent out a note to all 1050 homes that had their ceilings pumped full of Mr Fluffy asbestos during the 1960s and '70s. The mail-out warned owners that their houses could contain residual asbestos and they should get an assessor in to check - particularly before undertaking even minor building work.

The mail-out also revealed at least one instance of a Mr Fluffy house slipping through the net and being declared free of asbestos in its lease conveyancing report. Home owner Tim Lyon organised an inspection last month that confirmed Mr Fluffy in his walls and subfloors.

Workplace Safety Minister Simon Corbell said an audit of paperwork surrounding all Mr Fluffy-affected homes was continuing and that an investigation into how Mr Lyon's house was cleared of having asbestos at the point of sale was also under way.

''Any potential issues for other homes that are identified as part of this investigation will be addressed,'' Mr Corbell said.

The federal government spent $100 million removing Mr Fluffy from affected homes over five years from 1988. The clean-up was initiated in response to the obvious danger to home owners of having loose fibres of a type 1 carcinogen in their roof spaces.

But the asbestos experts agree that the vast majority of these houses probably still contain at least small amounts of the hazardous material - backed up by the test results of the past few weeks.

Mr Keane said all Mr Fluffy houses should have been demolished.

''Yes, in hindsight, it would have been better to take them apart and bury them, but the asbestos legislation was still in its infancy and awareness was not like it is today,'' he said. ''Still, a number of owners feel like they have the Sword of Damocles hanging over their head.''

One of the two major contractors for the federal removal program, Arthur Watson, said it had been a massive and unprecedented job to

clear Mr Fluffy from Canberra homes. His company, BRS, had worked on almost 700 homes and was given the brief to ''remove all visible and accessible asbestos'', which he said had included wall cavities as far as they could see and reach. ''We did clean the walls and get in under the subfloors as far as we were able to,'' he said.

Mr Watson meanwhile described as ''insane'' the ACT government's refusal to release a list of the 1050 original Mr Fluffy houses to tradespeople, saying they risked exposure during small jobs and renovations.

The government is looking at changes to information and legislation around Mr Fluffy homes.

Mr Keane said he could understand how nervous some home owners might be about that information affecting their property prices if it became public.

''There is a lot of fear about asbestos and you don't want to frighten people,'' he said.

''But no one is going to say there is a safe level of exposure to this stuff.''

Mr Keane said in his recent assessments of homes, asbestos readings had varied from home to home. ''Some dust samples have microscopic levels, but in one house it was on top of the fridge.''

He said a common problem appeared to be that asbestos had settled in and around cornices when it was originally pumped into roof spaces. But with age and movement of homes, it was starting to be exposed when the cornices began to peel away from the wall.