Qantas’ potential acquisition of Ticketek and its owner TEG is now in jeopardy after the airline was sued by Australia’s competition regulator.

According to court filings, The Australian Competition and Consumer Commission (ACCC) said that Qantas sold tickets to thousands of flights after they were cancelled. Qantas has since let go of chief executive Alan Joyce and hired its first female CEO, however, the airline’s reputation is at risk. Rico Merkert, deputy director of Sydney University’s Institute of Transport and Logistics Studies, told Reuters that the ACCC filing “could be detrimental for the Qantas brand.”

Qantas was looking into buying the TEG Group, which owns Ticketek, from its current owner Silver Lake with Kohlberg Kravis Roberts (KKR & Co. Inc. The acquisition, alike its purchase of TripADeal, would coincide with its Qantas Frequent Flyer Program. Blackstone is also eyeing the deal as its second contender. However, the sale process has reportedly been stalled.

Ticketek currently serves as the largest ticketing provider across Australia and New Zealand, selling 30 million tickets annually. The business is estimated to be worth $2 billion, however, MarketScreener reports that Silver Lake is looking for a sale between $2.5 and $3 billion.

Earlier this year, Ticketek and Spotify announced a groundbreaking partnership, as Ticketek became the official ticketing partner for Spotify’s Live Events Feed for events in Australia.