The owners of two houses on prime Wigan land which were demolished despite being in a conservation area could face legal action.
Two detached homes in Wigan Lane, one Victorian, the other early Edwardian, were bulldozed without permission from Wigan Council.
The action took place over a Bank Holiday weekend in May, meaning that town hall bosses were unaware of the work until after it had taken place.
The empty properties have been the subject of on-going correspondence between the Metro and the owners over their stated intention to flatten them.
The buildings had originally been approved for demolition by planners to make way for flats more than five years ago.
But the permission was not acted upon by the previous owners.
The houses then received legal protection when the Wigan Lane Conservation Area, originally approved by councillors more than two decades ago, was extended to include the two houses in the autumn of 2007.
So destroying them without the permission of the local authority could be a breach of planning laws.
Coun Gareth Fairhurst is concerned that those involved in demolishing the homes will go unpunished.
He said: "I have got grave concerns and I believe some action should be taken.
"If you let these people off the hook developers will keep knocking houses and trees down without any recourse.
"They will laugh in the face of justice."
Wigan Council says its planning and legal department is still seeking advice on the matter and that it was treating the demolition as a serious breach of planning regulations.
A spokesman said: "Wigan Council takes any possible breaches of planning regulations extremely seriously. We have taken legal advice over this issue and continue to do so.
"No decision with regards to action has been made at this time, however we need to ensure that any decision we do make is taken in the interests of the wider public."