The company has been listed as in receivership with McGrathNicol since August 29, plunging its Supercars future into serious doubt.
WAU declined to comment when contacted by Motorsport.com.
Mega Fuels joined the team as the primary backer for the 2019 season, WAU turning down an extension with former sponsor Boost Mobile for a lucrative new naming rights deal.
Mega had previously been involved in Jason Bright's Tickford-run entry, as well as backing Garry Jacobson's Super2 programme.
WAU is already playing a key role in the 2020 Supercars silly season, with terms for a deal with Chaz Mostert understood to have been agreed.
Current driver James Courtney, meanwhile, has confirmed he'll depart the squad at the end of 2019.