The findings of a report on potential future uses of the former National Museum of Costume near New Abbey will be released "shortly".
The decision to close Shambellie House was confirmed last year.
Galloway and West Dumfries MSP Alex Fergusson has criticised the condition of the building and the delay in releasing a report into its future.
A Scottish government spokesman said it had now received the feasibility study and would "share the findings" soon.
There was cross-party condemnation of the closure and repeated attempts to have the move postponed.
However, National Museums Scotland confirmed in February last year that the museum - which opened in 1982 - would not reopen for the summer season.
It vacated the building in September 2013 when responsibility for the site reverted to the Scottish government.
Mr Fergusson said it had failed to deliver on promises of a "new offering for Dumfries and Galloway".
"So far, it would appear that that 'new offering' consists of neglecting the grounds and external upkeep of Shambellie to the extent that the grounds - formerly maintained to the highest degree - are now just a neglected shambles," he said.
"This is simply not good enough."
He said that a report on the future was due in November but had been delayed until the spring.
He said he understood that it had been sitting with the Scottish government since February.
Mr Fergusson called on the Scottish government to maintain the grounds to their "previously high standards" until its future was decided.
National Museums Scotland said it had provided information for the study.
A spokeswoman added: "We continue to deliver a national museums service within Dumfries and Galloway through enhancing our programme of loans to local museums, establishing partnerships around specific projects and outreach activity with schools and other groups."
The Scottish government said it had "engaged extensively" with Dumfries and Galloway Council and National Museums Scotland over the issue.
It said it had made £20,000 available to the council last year for a feasibility study to consider potential uses for Shambellie House.
The Princes Regeneration Trust was commissioned to carry out this work.
"We have now received the feasibility study and will share the findings shortly," a spokesman added.