SYDNEY—Australian auction houses were expected to lodge a formal complaint with the Australian Competition and Consumer Commission this week against their rival, Menzies Art Brands, reports the Australian.

The complaint calls out several practices at the auction businesses run by chief executive Rod Menzies, including selling and rebuying the same works at auction, publishing questionable provenance notes, and obscuring ownership details. Menzies has also been accused of not disclosing guarantees on works offered at auction.

Academic and art valuer Meaghan Wilson-Anastasios told an Australian television program that if the accusations are true, then Menzies "has dramatically inflated the Australian art market, and with it inflated buyer confidence."

Menzies's actions, if true, have "essentially put in place, or contributed to, the factors that could pre-empt a market collapse," she added.

Menzies is known for his tenacity in business and for his desire to surpass Sotheby's in the market. Last year, his two businesses sold a combined $64.4 million (U.S. $60.6 million) of art at auction, according to the Australian, beating Sotheby's by more than $12 million.