Mrs Wong resigned her ministerial portfolios on Friday after admitting her husband Sammy conducted personal business during the trip, which is against the rules covering the use of the rebate perk for MPs and their spouses.
Labour MP Pete Hodgson yesterday released an extract from a Chinese local government website which discussed "minister" Mrs Wong's visit, while at the same time talking up the potential of the hovercraft business her husband was involved in when he conducted business on the 2008 trip.
Mr Hodgson also wants answers to questions about why businesses owned by Mr Wong were registered at Mrs Wong's Botany Downs electorate office.
Parliament's rules are clear about keeping public and private interests separate.
Labour is also criticising Prime Minister John Key, who has said Mrs Wong shouldn't say anything until a parliamentary inquiry into her previous travel claims has been completed.
"He is giving her advice to put her head down and just wait, and that is not okay, that's not the open, transparent government that he promised us," Mr Hodgson said.
