The company was registered in November.
Germanovitch also owns the 1198ha Mt Potts Station and lodge in the Rangitata Valley.
It was purchased in 2011 for $3.7m following Overseas Investment Office approval.
The businessman also bought one of the grandest but run-down mansions in Devonport, Auckland, in 2013 and embarked on a major renovation.
Germanovitch now owns a slice of central Ashburton after the purchase of the three-storey former council administration building and 5059 sq m parcel of land was settled on Friday.
Germanovitch's total known assets were reported in 2022 to amount to $13.5m.
Ashburton District Council chief executive Hamish Riach said the settlement had been expected at the end of January but it was brought forward by agreement.
"The paperwork has now been completed and the new owner will no doubt release plans for the site when they are ready."
The council sold the former public library building for $1.1m last year to CBR Properties Ltd, which plans to renovate the building into a boutique hotel.
It also sold two relocatable buildings for $160,000.
The project also received $20m from the government's shovel-ready infrastructure programme.
That reduces the total build cost of the building for the ratepayers to under $40m.
By Jonathan Leask, Local Democracy Reporter
■ LDR is local body journalism co-funded by RNZ and NZ On Air.