Cabinet minister Peter Dutton says the royal commission is a good opportunity to examine the link between industry superannuation funds and unions.
Under the terms of reference announced by Prime Minister Malcolm Turnbull on Thursday, the inquiry will examine "the use by a financial services entity of superannuation members' retirement savings for any purpose that does not meet community standards and expectations or is otherwise not in the best interest of members".
Research released by right-wing think tank the Institute of Public Affairs this week found between 2013 and mid-2017 trade unions received $18.4 million via directors' fees from industry superannuation funds.
The largest recipient was the Construction Forestry Mining and Energy Union (CFMEU) ($2.9 million).
Mr Dutton said while the royal commission was primarily looking at banks "there's also another element to it".
"That is to have a look at some aspects within the industry super funds which have union members and whatnot on the board," Mr Dutton told 2GB radio on Thursday.
"I think people lose a lot of their super through fees and through donations and all sorts of support for unions.
"So I think it's a good opportunity in that sense to have a look at the detail and people can put all of that information forward and we can see the recommendations from the commission," he said.
Unions have described the IPA report as misleading and politically motivated and defended the receipt of fees as helping workers' representatives fight for higher wages and conditions.