Work has resumed on two recent days at the Chinese-owned Blue Lake Dairy Group factory at Tantanoola.
Sources have said the purpose of the activity on August 19 and 24 was to fill outstanding orders.
An employee said their wages were up to date but the future of the Princes Highway plant remained uncertain.
All 12 employees had earlier been stood down on August 5 and production ceased.
The workers were told rent was owed on the facility which has created infant milk formula for several years for domestic and overseas markets.
The SE Voice has been told security personnel went to the factory on August 5 and locksmiths changed the locks on doors and gates.
The long-time freehold owner is McDonnell Industrial Pty Ltd which is a South East family-owned company.
The SE Voice has attempted to contact BLDG for comment.
BLDG started blending base milk powder into infant formula in 2016 and its further stages and major capital investment have yet to come to fruition.
There have been proposals to convert “wet milk” into powder requiring a workforce of 150.