The head of one of the country's largest industry superannuation funds, Hostplus chief executive David Elia, has been forced to defend spending members' money on entertaining employers at the Australian Open, as well as splurging on a lavish dinner for staff at Melbourne's Flower Drum restaurant.

The Hayne royal commission also heard Mr Elia’s decision to give Australian Open tickets to his wife and children and the use his corporate credit card to accumulate frequent flyer points was investigated by the Australian Prudential Regulation Authority after a tip off from an anonymous whistleblower.

The royal commission into financial misconduct has turned its attention to the $2.6 trillion superannuation industry, with Commonwealth Bank and Suncorp's wealth management arms also grilled on Tuesday. The royal commission is looking at example of misuse of members' money and inappropriate fees by both union-backed industry and for-profit private funds.

Mr Elia, who runs the $40 billion Hostplus fund on behalf of workers mostly in the hospitality industry, defended the use of Australian Open tickets for his family, indicating they were spares.

"When we invite our clients, we do invite their partners to come along," Mr Elia said.