Prime Minister Tony Abbott says Assistant Treasurer Arthur Sinodinos has his full confidence after his prior business dealings were aired at a NSW anti-corruption hearing.
An Independent Commission Against Corruption hearing in NSW on Monday heard Senator Sinodinos stood to earn as much as $20 million in personal profits working for a company linked to crooked former state Labor minister Eddie Obeid.
On Tuesday, Mr Abbott gave his support to the Senator under questioning from opposition MPs, describing his colleague as a long and faithful servant of the Parliament.
"The short answer is 'yes'," Mr Abbott said, when asked during question time if the Assistant Treasurer retained his support.
Mr Abbott stressed that the matters before the NSW ICAC related to events prior to Senator Sinodinos' entry to Parliament.
"There are important matters being investigated by the NSW independent commission against corruption in respect of Sinodinos, the matters in question happened prior to his entering Parliament and becoming a minister," he said.
"The Senator has been been asked to assist an inquiry into a particular company. He is doing so fully and frankly as you'd expect.
"Senator Sinodinos has served our country long and faithfully as a Treasury official and as the chief of staff to a PM [John Howard] as well as a member of this Parliament."
Mr Abbott also said he stood by comments he made six months ago that he would not appoint Senator Sinodinos to a ministry "if there was any cloud hanging over him".
In the Senate question time, Labor senator Penny Wong asked Senator Sinodinos whether he had abided by ministerial standards in his dealings with Obeid-linked Australian Water Holdings. She questioned whether he opened doors to the Liberal Party in his role on the board of AWH.
Senator Sinodinos said he could not comment on the matters before ICAC.
''Watch this space,'' he said. ''I will be vindicated.''
At the end of question time in the Senate, Senator Wong made a statement saying the chamber had witnessed a ''cover up'' by the Abbott government.
''There are some extraordinarily serious public allegations made against the Minister,'' she said.
''You would have thought [Sinodinos] would have taken the opportunity in question time today to front the Australian people.''
Senator Sinodinos had failed to disclose the ''enormous'' financial benefit he stood to receive, she added.
Senator Wong described Senator Sinodinos' previous statement to the Senate as ''inadequate at best and deliberately obfuscating at the worst''.
After Senator Wong sat down, Liberal Senator Simon Birmingham said it was ''outrageous'' that Labor had tried to ''operate some sort of kangaroo court'' to ''smear'' the Assistant Treasurer.