Tim Crakanthorp's in-laws have lodged a development application to build a new light industrial building on one of their properties in Georgetown.
The Newcastle MP is being investigated by the Independent Commission Against Corruption after allegedly failing to disclose the extent of his extended family's property interests in the Hunter.
One of the Manitta family properties at 8 Christo Road, Georgetown, is now the subject of a $700,000 proposal to replace a commercial building on the 860-square metre site.
The Manitta family owns eight commercial properties in Broadmeadow and Christo roads, near the government's proposed Hunter Park sports, entertainment and residential redevelopment precinct.
Government agencies have a strategy to rezone privately owned commercial land in Broadmeadow for housing, which could increase the value of some property in the suburb.
Mr Crakanthorp told Parliament last month that he had included in his first ministerial disclosure this year that his father-in-law, Joe Manitta, owned property at Broadmeadow but that at a later date he became aware "the properties owned within Broadmeadow by my in-laws also now represented a conflict of interest".
A Cabinet Office review conducted after Mr Crakanthorp's sacking from state cabinet in early August found the MP's failure to disclose properties owned by his family had not compromised decision-making and governance related to Hunter Park.
The Newcastle Herald does not suggest any Manitta family members have done anything wrong.
The ICAC confirmed last week that it had started investigating whether Mr Crakanthorp substantially breached the ministerial code of conduct.
