Yesterday they decided to put a stopwork order on the cottage at 94 Merri Street.

Council officers described it as ``perhaps the most important heritage site in Warrnambool and an irreplaceable part of our history''.

The move follows a request on Tuesday by the property owner for a demolition permit after a work prohibition notice was issued by WorkSafe on Monday.

A spokeswoman for Heritage Victoria told The Standard yesterday it wanted to ensure demolition did not occur until the building's condition could be investigated in conjunction with the city council.

``Our hope is it can be retained,'' she said.

The WorkSafe inspector said components of the building had lost structural integrity and it was a death trap. Workers had been involved with preparing the old building for extensions.

``Persons conducting works within this structure or adjacent to this structure are at risk of suffering serious injury or death in the event of a collapse occurring at this workplace,'' the safety report said.

Heritage Victoria is also investigating the owner's compliance with a heritage permit issued for works in January 2007. ``The permit included several conditions to ensure the structural integrity of the building was protected during the works,'' a spokeswoman said.

Council officers said stabilising work had not been completed to comply with permit conditions for the extensions.

The property, which has ocean views and is opposite Flagstaff Hill Maritime Village, was bought in 2000 by developer Terry Board.

He had planned to replace it until Heritage Victoria placed it under official protection two years later. Then in October 2003 it was badly damaged by fire and was spray-painted by graffiti vandals as it fell into disrepair.

It is considered significant because it was built as early as 1848 as a general store and is a rare example of pre-gold rush Georgian architecture.