Details of its financial situation – it has Aus$12m (£7m) in debts and assets of just Aus$3m (£1.7m) – emerged at a creditors’ meeting on January 4.
Director and joint founder Paul Sumner appointed BDO as voluntary administrator on December 21 after believing Mossgreen was insolvent.
A BDO spokesperson said: "Mossgreen is now insolvent and the administrators are in charge of the business and its assets."
Sumner remains a director of the company but during administration his powers are suspended.
He told ATG that he hoped “no vendors or artists will be out-of-pocket”.
The combined auctioneer and art gallery, set up by Sumner and Amanda Swanson in 2004, has expanded quickly, including merging with Leski Auctions in 2013 and buying Webb’s of Auckland in 2015 and opening a new gallery and event space in Sydney in 2016.
The firm’s primary investor, businessman Jack Gringlas, is thought to be the biggest creditor but the bulk of those owed money are believed to be consignors. BDO said creditors will vote at a second meeting on whether the company goes into liquidation or a deed of company arrangement is approved.
According to Australian newspaper The Age auctions scheduled in Melbourne will go ahead from February. Mossgreen's Auckland office will re-open but the branch in Sydney's Woollahra will remain close.