Mining industry figure Ian Middlemas is among a group of investors being pursued by Westpac Banking Corp for more than $33 million over a debt used to finance an expensive resort in Western Australia’s south-west that went sour.

The syndicate members appear to have been left exposed to the large debt after construction delays and cost blowouts at the Aqua Resort in Busselton coincided with a sharp downturn in the once-booming coastal precinct.